diff --git a/Entities/Contracts/AppMainStruct.cs b/Entities/Contracts/AppMainStruct.cs
new file mode 100644
index 0000000..97b856a
--- /dev/null
+++ b/Entities/Contracts/AppMainStruct.cs
@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.Contracts
+{
+	public enum Layout : byte
+	{
+		horizontal = 0,
+		vertical = 1,
+
+		Auto = 2
+	}
+
+	public enum Publisher : byte
+	{
+		Unknown = 0,
+		统编版,
+		部编版,
+	}
+
+	public enum Grade : byte
+	{
+		Unknown = 0,
+		一年级 = 1,
+		二年级 = 2,
+		三年级 = 3,
+		四年级 = 4,
+		五年级 = 5,
+		六年级 = 6
+	}
+
+	public enum DifficultyLevel : byte
+	{
+		easy,
+		medium,
+		hard
+	}
+
+	public enum QuestionType : byte
+	{
+		Unknown = 0,
+		Spelling,           // 拼写
+		Pronunciation,      // 给带点字选择正确读音
+		WordFormation,      // 组词
+		FillInTheBlanks,    // 选词填空 / 补充词语
+		SentenceDictation,  // 默写句子
+		SentenceRewriting,  // 仿句 / 改写句子
+		ReadingComprehension, // 阅读理解
+		Composition         // 作文
+							
+	}
+
+	public enum SubjectAreaEnum : byte
+	{
+		Unknown = 0,         
+		Mathematics,     // 数学
+		Physics,         // 物理
+		Chemistry,       // 化学
+		Biology,         // 生物
+		History,         // 历史
+		Geography,       // 地理
+		Literature,      // 语文/文学
+		English,         // 英语
+		ComputerScience, // 计算机科学
+	}
+
+	public enum QuestionGroupState : byte
+	{
+		Standalone,
+		Group,
+		Subquestion
+	}
+
+}
diff --git a/Entities/Contracts/Assignment.cs b/Entities/Contracts/Assignment.cs
index 7e7d8a2..36e3742 100644
--- a/Entities/Contracts/Assignment.cs
+++ b/Entities/Contracts/Assignment.cs
@@ -24,32 +24,36 @@ namespace Entities.Contracts
 		public string Description { get; set; }
 
 		[Column("subject_area")]
-		public string SubjectArea { get; set; }
+		public SubjectAreaEnum SubjectArea { get; set; }
 
 		[Required]
 		[Column("due_date")]
 		public DateTime DueDate { get; set; }
 
 		[Column("total_points")]
-		public float? TotalPoints { get; set; }
+		public byte TotalQuestions { get; set; }
+
+		[Column("score")]
+		public float Score { get; set; }
 
 		[Column("created_by")]
-		[ForeignKey("Creator")]
-		public Guid CreatedBy { get; set; }
+		public Guid CreatorId { get; set; }
 
 		[Column("created_at")]
 		public DateTime CreatedAt { get; set; }
 
 		[Column("updated_at")]
-		public DateTime UpdatedAt { get; set; }
+		public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
 
 		[Column("deleted")]
-		public bool IsDeleted { get; set; }
+		public bool IsDeleted { get; set; } = false;
 
 		// Navigation Properties
+		
+		[ForeignKey(nameof(CreatorId))]
 		public User Creator { get; set; }
 		public ICollection<AssignmentClass> AssignmentClasses { get; set; }
-		public ICollection<AssignmentGroup> AssignmentGroups { get; set; }
+		public AssignmentStruct ExamStruct { get; set; }
 		public ICollection<AssignmentAttachment> AssignmentAttachments { get; set; }
 		public ICollection<Submission> Submissions { get; set; }
 
@@ -58,7 +62,6 @@ namespace Entities.Contracts
 			Id = Guid.NewGuid();
 
 			Submissions = new HashSet<Submission>();
-			AssignmentGroups = new HashSet<AssignmentGroup>();
 			AssignmentClasses = new HashSet<AssignmentClass>();
 			AssignmentAttachments = new HashSet<AssignmentAttachment>();
 		}
diff --git a/Entities/Contracts/AssignmentQuestion.cs b/Entities/Contracts/AssignmentQuestion.cs
index 0b9d1cd..a7b836b 100644
--- a/Entities/Contracts/AssignmentQuestion.cs
+++ b/Entities/Contracts/AssignmentQuestion.cs
@@ -6,6 +6,7 @@ using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using Entities.DTO;
 
 namespace Entities.Contracts
 {
@@ -17,41 +18,43 @@ namespace Entities.Contracts
 		public Guid Id { get; set; }
 
 		[Column("question_id")]
-		public Guid? QuestionId { get; set; } // 设为可空
-
-		// 当 IsGroup 为 true 时，此为 QuestionGroup 的外键
-		[Column("question_group_id")] // 新增一个外键列
-		public Guid? QuestionGroupId { get; set; } // 设为可空
+		public Guid QuestionId { get; set; } 
 
 		[Required]
 		[Column("group_id")]
 		[ForeignKey("AssignmentGroup")]
-		public Guid AssignmentGroupId { get; set; }
-
+		public Guid AssignmentStructId { get; set; }
 
 		[Required]
 		[Column("question_number")]
-		public byte QuestionNumber { get; set; }
+		public byte Index { get; set; }
 
 
+		[Column("parent_question_group_id")]
+		public Guid? ParentAssignmentQuestionId { get; set; }
+
+		[Column("group_state")]
+		public QuestionGroupState GroupState { get; set; } = QuestionGroupState.Standalone;
+
 		[Column("created_at")]
 		public DateTime CreatedAt { get; set; }
 
 		[Column("score")]
 		public float? Score { get; set; }
 
-		[Required]
-		[Column("bgroup")]
-		public bool IsGroup { get; set; }
 
 		[Column("deleted")]
 		public bool IsDeleted { get; set; }
 
 
 		public Question Question { get; set; }
-		public QuestionGroup QuestionGroup { get; set; }	
+		public AssignmentStruct AssignmentStruct { get; set; }
 		public ICollection<SubmissionDetail> SubmissionDetails { get; set; }
-		public AssignmentGroup AssignmentGroup { get; set; }
+
+		[ForeignKey(nameof(ParentAssignmentQuestionId))]
+		public AssignmentQuestion? ParentAssignmentQuestion { get; set; }
+		public ICollection<AssignmentQuestion> ChildrenAssignmentQuestion { get; set; } = new List<AssignmentQuestion>();
+
 
 		public AssignmentQuestion()
 		{
diff --git a/Entities/Contracts/AssignmentGroup.cs b/Entities/Contracts/AssignmentStruct.cs
similarity index 61%
rename from Entities/Contracts/AssignmentGroup.cs
rename to Entities/Contracts/AssignmentStruct.cs
index 623fa7d..4b61e9c 100644
--- a/Entities/Contracts/AssignmentGroup.cs
+++ b/Entities/Contracts/AssignmentStruct.cs
@@ -5,11 +5,12 @@ using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Runtime.InteropServices;
 
 namespace Entities.Contracts
 {
 	[Table("assignment_group")]
-	public class AssignmentGroup
+	public class AssignmentStruct
 	{
 		[Key]
 		[Column("id")]
@@ -26,35 +27,34 @@ namespace Entities.Contracts
 
 		[Column("descript")]
 		[MaxLength(65535)] 
-		public string Descript { get; set; }
+		public string Description { get; set; }
 
+		[Column("layout")]
+		public Layout Layout { get; set; }	
 
 		[Column("total_points")]
-		public float? TotalPoints { get; set; }
+		public float? Score { get; set; }
 
-		[Column("number")]
-		public byte Number { get; set; }
+		[Column("index")]
+		public byte Index { get; set; }
 
 		[Column("parent_group")]
-		public Guid? ParentGroup { get; set; }
+		public Guid? ParentStructId { get; set; }
 
 		[Column("deleted")]
-		public bool IsDeleted { get; set; }
-
-		[Column("valid_question_group")]
-		public bool ValidQuestionGroup { get; set; }
+		public bool IsDeleted { get; set; } = false;
 
 		// Navigation Properties
 		public Assignment? Assignment { get; set; }
-		public AssignmentGroup? ParentAssignmentGroup { get; set;}
-		public ICollection<AssignmentGroup> ChildAssignmentGroups { get; set; }
+		public AssignmentStruct? ParentStruct { get; set;}
+		public ICollection<AssignmentStruct> ChildrenGroups { get; set; }
 		public ICollection<AssignmentQuestion> AssignmentQuestions { get; set; }
 
 
-		public AssignmentGroup()
+		public AssignmentStruct()
 		{
 			Id = Guid.NewGuid();
-			ChildAssignmentGroups = new HashSet<AssignmentGroup>();
+			ChildrenGroups = new HashSet<AssignmentStruct>();
 			AssignmentQuestions = new HashSet<AssignmentQuestion>();
 		}
 	}
diff --git a/Entities/Contracts/ClassTeacher.cs b/Entities/Contracts/ClassTeacher.cs
index 7974b37..3434624 100644
--- a/Entities/Contracts/ClassTeacher.cs
+++ b/Entities/Contracts/ClassTeacher.cs
@@ -22,6 +22,6 @@ namespace Entities.Contracts
 		public User Teacher { get; set; }
 
 		[Column("subject_taught")]
-		public string SubjectTaught { get; set; }
+		public SubjectAreaEnum SubjectTaught { get; set; }
 	}
 }
diff --git a/Entities/Contracts/Question.cs b/Entities/Contracts/Question.cs
index a51e91d..16f80c9 100644
--- a/Entities/Contracts/Question.cs
+++ b/Entities/Contracts/Question.cs
@@ -16,36 +16,43 @@ namespace Entities.Contracts
 		public Guid Id { get; set; }
 
 		[Required]
-		[Column("question_text")]
+		[Column("title")]
 		[MaxLength(65535)]
-		public string QuestionText { get; set; }
+		public string Title { get; set; }
+
+		[Column("answer")]
+		[MaxLength(65535)]
+		public string? Answer { get; set; }
+
+		[Column("description")]
+		public Guid? DescriptionId { get; set; }
 
 		[Required]
-		[Column("question_type")]
+		[Column("type")]
 		[MaxLength(20)]
-		public QuestionType QuestionType { get; set; } 
-
-		[Column("correct_answer")]
-		[MaxLength(65535)]
-		public string CorrectAnswer { get; set; }
-
-		[Column("question_group_id")]
-		public Guid? QuestionGroupId { get; set; }
+		public QuestionType Type { get; set; } = QuestionType.Unknown;
 
 		[Column("difficulty_level")]
 		[MaxLength(10)] 
-		public DifficultyLevel DifficultyLevel { get; set; } 
+		public DifficultyLevel DifficultyLevel { get; set; } = DifficultyLevel.easy;
 
 		[Column("subject_area")]
-		public SubjectAreaEnum SubjectArea { get; set; }
+		public SubjectAreaEnum SubjectArea { get; set; } = SubjectAreaEnum.Unknown;
+
 
 		[Column("options")]
 		public string? Options { get; set; }
 
+		[Column("key_point")]
+		public Guid? KeyPointId { get; set; }
+
+		[Column("lesson")]
+		public Guid? LessonId { get; set; }
+
+
 		[Required]
 		[Column("created_by")]
-		[ForeignKey("Creator")]
-		public Guid CreatedBy { get; set; }
+		public Guid CreatorId { get; set; }
 
 		[Column("created_at")]
 		public DateTime CreatedAt { get; set; }
@@ -56,54 +63,30 @@ namespace Entities.Contracts
 		[Column("deleted")]
 		public bool IsDeleted { get; set; }
 
-		[Column("valid_question")]
-		public bool ValidQuestion { get; set; }
 
 		// Navigation Properties
+		[ForeignKey(nameof(CreatorId))]
 		public User Creator { get; set; }
-		public QuestionGroup QuestionGroup { get; set; }
-		public ICollection<AssignmentQuestion> AssignmentQuestions { get; set; }
+
+		[ForeignKey(nameof(DescriptionId))]
+		public QuestionContext Description { get; set; }
+		public Question? ParentQuestion { get; set; }
+		public ICollection<Question>? ChildrenQuestion { get; set; }
+
+		[ForeignKey(nameof(KeyPointId))]
+		public KeyPoint? KeyPoint { get; set; }
+		[ForeignKey(nameof(LessonId))]	
+		public Lesson? Lesson { get; set; }
+		
+		public ICollection<AssignmentQuestion>? AssignmentQuestions { get; set; }
 
 		public Question()
 		{
 			Id = Guid.NewGuid();
 			AssignmentQuestions = new HashSet<AssignmentQuestion>();
+			ChildrenQuestion = new HashSet<Question>();	
 		}
 	}
 
-	public enum DifficultyLevel
-	{
-		easy,
-		medium,
-		hard
-	}
 
-	public enum QuestionType
-	{
-		Unknown, // 可以有一个未知类型或作为默认
-		Spelling,           // 拼写
-		Pronunciation,      // 给带点字选择正确读音
-		WordFormation,      // 组词
-		FillInTheBlanks,    // 选词填空 / 补充词语
-		SentenceDictation,  // 默写句子
-		SentenceRewriting,  // 仿句 / 改写句子
-		ReadingComprehension, // 阅读理解
-		Composition         // 作文
-							// ... 添加您其他题目类型
-	}
-
-	public enum SubjectAreaEnum // 建议命名为 SubjectAreaEnum 以避免与属性名冲突
-	{
-		Unknown,         // 未知或默认
-		Mathematics,     // 数学
-		Physics,         // 物理
-		Chemistry,       // 化学
-		Biology,         // 生物
-		History,         // 历史
-		Geography,       // 地理
-		Literature,      // 语文/文学
-		English,         // 英语
-		ComputerScience, // 计算机科学
-						 // ... 你可以根据需要添加更多科目
-	}
 }
diff --git a/Entities/Contracts/QuestionContext.cs b/Entities/Contracts/QuestionContext.cs
new file mode 100644
index 0000000..ce4e7fc
--- /dev/null
+++ b/Entities/Contracts/QuestionContext.cs
@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations.Schema;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.Contracts
+{
+	public class QuestionContext
+	{
+		public Guid Id { get; set; }
+
+		public string Description { get; set; } = string.Empty;
+
+		[InverseProperty(nameof(Question.Description))]	
+		public ICollection<Question> Questions { get; set; } = new List<Question>();
+
+
+		public QuestionContext()
+		{
+			Questions = new HashSet<Question>();
+		}
+	}
+}
diff --git a/Entities/Contracts/QuestionGroup.cs b/Entities/Contracts/QuestionGroup.cs
deleted file mode 100644
index df6f656..0000000
--- a/Entities/Contracts/QuestionGroup.cs
+++ /dev/null
@@ -1,79 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel.DataAnnotations.Schema;
-using System.ComponentModel.DataAnnotations;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Entities.Contracts
-{
-	[Table("question_groups")]
-	public class QuestionGroup
-	{
-		[Key]
-		[Column("id")]
-		public Guid Id { get; set; }
-
-		[Column("title")]
-		[MaxLength(255)]
-		public string Title { get; set; }
-
-		[Required]
-		[Column("description")]
-		[MaxLength(65535)]
-		public string Description { get; set; }
-
-		[Column("type")]
-		[MaxLength(50)]
-		public string Type { get; set; }
-
-		[Column("difficulty_level")]
-		[MaxLength(10)]
-		public DifficultyLevel DifficultyLevel { get; set; }
-
-		[Column("subject_area")]
-		public SubjectAreaEnum SubjectArea { get; set; }
-
-		[Column("total_questions")]
-		public int TotalQuestions { get; set; } = 0;
-
-		[Column("parent_question_group")]
-		public Guid? ParentQG { get; set; }
-
-		[Required]
-		[Column("created_by")]
-		[ForeignKey("Creator")]
-		public Guid CreatedBy { get; set; }
-
-		[Column("created_at")]
-		public DateTime CreatedAt { get; set; }
-
-		[Column("updated_at")]
-		public DateTime UpdatedAt { get; set; }
-
-		[Column("deleted")]
-		public bool IsDeleted { get; set; }
-
-		[Column("valid_group")]
-		public bool ValidGroup { get; set; }
-
-
-
-		public User Creator { get; set; }
-		public QuestionGroup ParentQuestionGroup { get; set; }
-		public ICollection<QuestionGroup> ChildQuestionGroups { get; set; }
-		public ICollection<AssignmentQuestion> AssignmentQuestions { get; set; }
-		public ICollection<Question> Questions { get; set; }
-
-		public QuestionGroup()
-		{
-			Id = Guid.NewGuid();
-			Questions = new HashSet<Question>();
-			CreatedAt = DateTime.UtcNow;
-			UpdatedAt = DateTime.UtcNow;
-			IsDeleted = false;
-			ValidGroup = true;
-		}
-	}
-}
diff --git a/Entities/Contracts/Submission.cs b/Entities/Contracts/Submission.cs
index 30affba..832da6f 100644
--- a/Entities/Contracts/Submission.cs
+++ b/Entities/Contracts/Submission.cs
@@ -41,7 +41,7 @@ namespace Entities.Contracts
 
 		[Column("graded_by")]
 		[ForeignKey("Grader")]
-		public Guid? GradedBy { get; set; }
+		public Guid? GraderId { get; set; }
 
 		[Column("graded_at")]
 		public DateTime? GradedAt { get; set; }
@@ -74,6 +74,5 @@ namespace Entities.Contracts
 		Resubmission,   // 待重新提交 (如果允许)
 		Late,           // 迟交
 		Draft,          // 草稿
-						// ... 添加你需要的其他状态
 	}
 }
diff --git a/Entities/Contracts/SubmissionDetail.cs b/Entities/Contracts/SubmissionDetail.cs
index eae0e4c..121b78f 100644
--- a/Entities/Contracts/SubmissionDetail.cs
+++ b/Entities/Contracts/SubmissionDetail.cs
@@ -23,7 +23,6 @@ namespace Entities.Contracts
 
 		[Required]
 		[Column("student_id")]
-		[ForeignKey("User")]
 		public Guid StudentId { get; set; }
 
 		[Required]
@@ -52,8 +51,11 @@ namespace Entities.Contracts
 		[Column("deleted")]
 		public bool IsDeleted { get; set; }
 
+		[ForeignKey(nameof(StudentId))]
+		public User Student { get; set; }
+
 		public Submission Submission { get; set; }
-		public User User { get; set; }
+
 		public AssignmentQuestion AssignmentQuestion { get; set; }
 
 		public SubmissionDetail()
diff --git a/Entities/Contracts/Textbook/KeyPoint.cs b/Entities/Contracts/Textbook/KeyPoint.cs
new file mode 100644
index 0000000..4f58dae
--- /dev/null
+++ b/Entities/Contracts/Textbook/KeyPoint.cs
@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.Contracts
+{
+	[Table("key_point")]
+	public class KeyPoint
+	{
+		[Key]
+		public Guid Id { get; set; }
+
+		[StringLength(255)]
+		public string Key { get; set; } = string.Empty;
+
+		
+		[Required]
+		public Guid LessonID { get; set; }
+
+		[ForeignKey(nameof(LessonID))]
+		public Lesson Lesson { get; set; }
+
+
+		public ICollection<Question> Questions { get; set; }
+
+		public KeyPoint()
+		{
+			Id = Guid.NewGuid();
+			Questions = new HashSet<Question>();
+		}
+	}
+}
diff --git a/Entities/Contracts/Textbook/Lesson.cs b/Entities/Contracts/Textbook/Lesson.cs
new file mode 100644
index 0000000..339689a
--- /dev/null
+++ b/Entities/Contracts/Textbook/Lesson.cs
@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.Contracts
+{
+	[Table("lesson")]
+	public class Lesson
+	{
+		[Key]
+		public Guid Id { get; set; }
+
+		[StringLength(255)]
+		public string Title { get; set; } = string.Empty;
+
+		public string Description { get; set; } = string.Empty;
+
+		[Required]
+		public Guid TextbookID { get; set; }
+
+
+		[ForeignKey(nameof(TextbookID))]
+		public Textbook Textbook { get; set; }
+
+		[InverseProperty(nameof(KeyPoint.Lesson))]
+		public ICollection<KeyPoint>? KeyPoints { get; set; }
+
+		[InverseProperty(nameof(Question.Lesson))]
+		public ICollection<Question>? Questions { get; set; }
+
+		[InverseProperty(nameof(LessonQuestion.Lesson))]
+		public ICollection<LessonQuestion>? LessonQuestions { get; set; } 
+
+
+
+		public Lesson()
+		{
+			Id = Guid.NewGuid();
+			KeyPoints = new HashSet<KeyPoint>();
+			Questions = new HashSet<Question>();	
+			LessonQuestions = new HashSet<LessonQuestion>();	
+		}
+	}
+}
diff --git a/Entities/Contracts/Textbook/LessonQuestion.cs b/Entities/Contracts/Textbook/LessonQuestion.cs
new file mode 100644
index 0000000..a498317
--- /dev/null
+++ b/Entities/Contracts/Textbook/LessonQuestion.cs
@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.Contracts
+{
+	[Table("lesson_question")]
+	public class LessonQuestion
+	{
+		[Key]
+		public Guid Id { get; set; }
+
+		[MaxLength(65535)]
+		public string Question { get; set; }
+
+		[Required]
+		public Guid LessonID { get; set; }
+
+		[ForeignKey(nameof(LessonID))]	
+		public Lesson Lesson { get; set; }
+
+		public LessonQuestion()
+		{
+			Id = Guid.NewGuid();
+		}
+
+	}
+}
diff --git a/Entities/Contracts/Textbook/Textbook.cs b/Entities/Contracts/Textbook/Textbook.cs
new file mode 100644
index 0000000..952f45b
--- /dev/null
+++ b/Entities/Contracts/Textbook/Textbook.cs
@@ -0,0 +1,36 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.Contracts
+{
+	[Table("textbook")]
+	public class Textbook
+	{
+		[Key]
+		public Guid Id { get; set; }
+
+		public Grade Grade { get; set; } = Grade.Unknown;
+
+		public string Title { get; set; } = string.Empty;
+
+		public Publisher Publisher { get; set; } = Publisher.部编版;
+
+		public SubjectAreaEnum SubjectArea { get; set; } = SubjectAreaEnum.Unknown;
+
+		[InverseProperty(nameof(Lesson.Textbook))]
+		public ICollection<Lesson> Lessons { get; set; }
+
+		public Textbook()
+		{
+			Id = Guid.NewGuid();
+			Lessons = new HashSet<Lesson>();
+		}
+	}
+
+}
diff --git a/Entities/DTO/AssignmentDto.cs b/Entities/DTO/AssignmentDto.cs
new file mode 100644
index 0000000..9a9af91
--- /dev/null
+++ b/Entities/DTO/AssignmentDto.cs
@@ -0,0 +1,9 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.DTO
+{
+}
diff --git a/Entities/DTO/AssignmentQuestionDto.cs b/Entities/DTO/AssignmentQuestionDto.cs
new file mode 100644
index 0000000..c4f7980
--- /dev/null
+++ b/Entities/DTO/AssignmentQuestionDto.cs
@@ -0,0 +1,25 @@
+using Entities.Contracts;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.DTO
+{
+	public class AssignmentQuestionDto
+	{
+		public float Score { get; set; } = 0;
+		public byte Index { get; set; } = 0;
+		public QuestionGroupState GroupState { get; set; } = QuestionGroupState.Standalone;
+
+
+
+		public AssignmentQuestionDto? ParentAssignmentQuestion { get; set; }
+		public ICollection<AssignmentQuestionDto> ChildrenAssignmentQuestion { get; set; } = new List<AssignmentQuestionDto>();
+
+
+
+		public QuestionDto Question { get; set; }
+	}
+}
diff --git a/Entities/DTO/ExamDto.cs b/Entities/DTO/ExamDto.cs
index c5b82d3..bda651c 100644
--- a/Entities/DTO/ExamDto.cs
+++ b/Entities/DTO/ExamDto.cs
@@ -1,4 +1,5 @@
-using System;
+using Entities.Contracts;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -7,36 +8,88 @@ using System.Xml.Serialization;
 
 namespace Entities.DTO
 {
+
+	public class AssignmentStructDto
+	{
+		public Guid Id { get; set; } = Guid.Empty;
+		public string Title { get; set; } = string.Empty;
+		public string Description { get; set; } = string.Empty;
+		public float Score { get; set; } = 0;
+		public byte Index { get; set; } = 0;
+		public Layout Layout { get; set; } = Layout.horizontal;
+
+
+
+
+		public ICollection<AssignmentQuestionDto> AssignmentQuestions { get; set; } = new List<AssignmentQuestionDto>();
+
+		public AssignmentStructDto? ParentStruct { get; set; }
+		public ICollection<AssignmentStructDto> ChildrenGroups { get; set; } = new List<AssignmentStructDto>();
+	}
+
+	public class AssignmentDto
+	{
+		public Guid Id { get; set; } = Guid.Empty;
+		public string Title { get; set; } = string.Empty;
+		public string Description { get; set; } = string.Empty;
+
+		public byte TotalQuestions { get; set; }
+		public float Score { get; set; } = 0;
+		public SubjectAreaEnum SubjectArea { get; set; } = SubjectAreaEnum.Unknown;
+		public DateTime CreatedAt { get; set; }
+		public DateTime UpdatedAt { get; set; }
+		public DateTime DueDate { get; set; }
+		public Guid CreatorId { get; set; }
+
+		public AssignmentStructDto ExamStruct { get; set; } = new AssignmentStructDto();
+	}
+
+	public class AssignmentClassDto
+	{
+		public AssignmentDto Assignment { get; set; }
+		public Class ClassId { get; set; }
+		public DateTime AssignedAt { get; set; }
+	}
+
+	public class QuestionContextDto
+	{
+		public Guid Id { get; set; } = Guid.Empty;
+		public string Description { get; set; } = string.Empty;
+	}
+
+
+
+
+
 	public class ExamDto
 	{
 		public Guid? AssignmentId { get; set; }
-		public string CreaterEmail { get; set; }	
+		public string CreaterEmail { get; set; }
 		public string AssignmentTitle { get; set; } = string.Empty;
 		public string Description { get; set; }
 		public string SubjectArea { get; set; }
-		public QuestionGroupDto QuestionGroups { get; set; } = new QuestionGroupDto();
+		public QuestionGroupDto ExamStruct { get; set; } = new QuestionGroupDto();
 	}
 
 	public class QuestionGroupDto
 	{
-		public byte Index { get; set; } 
+		public byte Index { get; set; }
 
 		public string? Title { get; set; }
 
 		public float Score { get; set; }
 
-		public string? Descript { get; set; } 
+		public string? Descript { get; set; }
 		public List<SubQuestionDto> SubQuestions { get; set; } = new List<SubQuestionDto>();
 		public List<QuestionGroupDto> SubQuestionGroups { get; set; } = new List<QuestionGroupDto>();
 
-		// 标记是否是一个具有上下文的单独问题
 		public bool ValidQuestionGroup { get; set; } = false;
 	}
 
 	public class SubQuestionDto
 	{
 
-		public byte Index { get; set; } 
+		public byte Index { get; set; }
 
 		public string? Stem { get; set; }
 
@@ -44,12 +97,11 @@ namespace Entities.DTO
 
 		public List<OptionDto> Options { get; set; } = new List<OptionDto>();
 
-		public string? SampleAnswer { get; set; } 
+		public string? SampleAnswer { get; set; }
 
-		public string? QuestionType { get; set; } 
+		public string? QuestionType { get; set; }
 		public string? DifficultyLevel { get; set; }
 
-		// 标记是否是一个独立的问题
 		public bool ValidQuestion { get; set; } = false;
 
 	}
@@ -64,13 +116,13 @@ namespace Entities.DTO
 	{
 		public static void Convert(this ExamDto examDto)
 		{
-			var qg = examDto.QuestionGroups;
+			var qg = examDto.ExamStruct;
 
 		}
 
 		public static void Convert(this QuestionGroupDto examDto)
 		{
-			if(examDto.ValidQuestionGroup)
+			if (examDto.ValidQuestionGroup)
 			{
 
 			}
diff --git a/Entities/DTO/QuestionDto.cs b/Entities/DTO/QuestionDto.cs
new file mode 100644
index 0000000..ca2d4fe
--- /dev/null
+++ b/Entities/DTO/QuestionDto.cs
@@ -0,0 +1,41 @@
+using Entities.Contracts;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations.Schema;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Entities.DTO
+{
+	public class QuestionDto
+	{
+		public Guid Id { get; set; } = Guid.Empty;
+
+		public string Title { get; set; } = string.Empty;
+
+		public QuestionContextDto? Description { get; set; }	
+
+		public QuestionType Type { get; set; } = QuestionType.Unknown;
+
+		public string? Answer { get; set; } = string.Empty;
+
+		public string? Options { get; set; }
+
+		public DifficultyLevel DifficultyLevel { get; set; } = DifficultyLevel.easy;
+
+		public SubjectAreaEnum SubjectArea { get; set; } = SubjectAreaEnum.Unknown;
+
+		public Guid CreatorId { get; set; }
+
+		public Guid? KeyPointId { get; set; }
+
+		public Guid? LessonId { get; set; }
+
+		public DateTime CreatedAt { get; set; }
+
+		public DateTime UpdatedAt { get; set; } = DateTime.Now;
+
+	}
+}
diff --git a/TechHelper.Client/Exam/ExamPaperExtensions .cs b/TechHelper.Client/Exam/ExamPaperExtensions .cs
index d4cb2e9..bea31f6 100644
--- a/TechHelper.Client/Exam/ExamPaperExtensions .cs	
+++ b/TechHelper.Client/Exam/ExamPaperExtensions .cs	
@@ -1,67 +1,173 @@
 using Entities.DTO;
 using System.Text.Json.Serialization;
 using System.Text.Json;
+using Entities.Contracts;
+using Microsoft.Extensions.Options;
 
 namespace TechHelper.Client.Exam
 {
+	public class ParentStructInfo
+	{
+		public string Number { get; set; }
+		public SubjectAreaEnum SubjectArea { get; set; }
+		public byte Index { get; set; }
+	}
+
 	public static class ExamPaperExtensions
 	{
-		public static ExamDto ConvertToExamDTO(this ExamPaper examPaper)
+		public static AssignmentDto ConvertToExamDTO(this ExamPaper examPaper)
 		{
-			ExamDto dto = new ExamDto();
+			AssignmentDto dto = new AssignmentDto();
 
-			dto.AssignmentTitle = examPaper.AssignmentTitle;
+			dto.Title = examPaper.AssignmentTitle;
 			dto.Description = examPaper.Description;
-			dto.SubjectArea = examPaper.SubjectArea;
-			dto.QuestionGroups.Title = examPaper.AssignmentTitle;
-			dto.QuestionGroups.Descript = examPaper.Description;
+
+			var SubjectArea = SubjectAreaEnum.Literature;
+			Enum.TryParse<SubjectAreaEnum>(examPaper.SubjectArea, out SubjectArea);
+			dto.SubjectArea = SubjectArea;
+
+			AssignmentStructDto examStruct = new AssignmentStructDto();
 
 			foreach (var qg in examPaper.QuestionGroups)
 			{
-				var qgd = new QuestionGroupDto();
-				ParseMajorQuestionGroup(qg, qgd, false);
-				dto.QuestionGroups.SubQuestionGroups.Add(qgd);
+				examStruct.ChildrenGroups.Add(ParseMajorQuestionGroup(qg));
+				examStruct.ChildrenGroups.Last().Index = (byte)(examStruct.ChildrenGroups.Count());
 			}
 
-
-			foreach (var question in examPaper.TopLevelQuestions)
-			{
-				if (question.SubQuestions != null && question.SubQuestions.Any())
-				{
-					var qgDto = new QuestionGroupDto
-					{
-						Title = question.Stem,
-						Score = (int)question.Score,
-						Descript = "",
-					};
-
-					qgDto.ValidQuestionGroup = !string.IsNullOrEmpty(qgDto.Descript);
-
-
-					ParseQuestionWithSubQuestions(question, qgDto, qgDto.ValidQuestionGroup);
-					dto.QuestionGroups.SubQuestionGroups.Add(qgDto);
-				}
-				else
-				{
-					var qgDto = new QuestionGroupDto
-					{
-						Title = question.Stem,
-						Score = (int)question.Score,
-						Descript = "",
-					};
-
-					qgDto.ValidQuestionGroup = !string.IsNullOrEmpty(qgDto.Descript);
-
-					var subQuestionDto = new SubQuestionDto();
-					ParseSingleQuestion(question, subQuestionDto, !qgDto.ValidQuestionGroup);
-					qgDto.SubQuestions.Add(subQuestionDto);
-					dto.QuestionGroups.SubQuestionGroups.Add(qgDto);
-				}
-			}
+			dto.ExamStruct = examStruct;
 
 			return dto;
 		}
 
+		private static AssignmentStructDto ParseMajorQuestionGroup(MajorQuestionGroup sqg)
+		{
+			var examStruct = new AssignmentStructDto();
+
+			if (sqg.SubQuestionGroups != null)
+			{
+
+				examStruct.Title = sqg.Title;
+				examStruct.Score = sqg.Score;
+				examStruct.ChildrenGroups = new List<AssignmentStructDto>();
+				sqg.SubQuestionGroups?.ForEach(ssqg =>
+				{
+					if (string.IsNullOrEmpty(ssqg.Descript))
+					{
+						examStruct.ChildrenGroups.Add(ParseMajorQuestionGroup(ssqg));
+						examStruct.ChildrenGroups.Last().Index = (byte)(examStruct.ChildrenGroups.Count());
+					}
+					else
+					{
+						examStruct.AssignmentQuestions.Add(ParseGroupToAssignmentQuestion(ssqg, false));
+						examStruct.AssignmentQuestions.Last().Index = (byte)(examStruct.AssignmentQuestions.Count());
+					}
+
+				});
+
+			}
+
+
+			if (sqg.SubQuestions != null)
+			{
+
+				sqg.SubQuestions?.ForEach(sq =>
+				{
+					if(sq.SubQuestions.Any())
+					{
+
+					}
+					examStruct.AssignmentQuestions.Add(ParseAssignmentQuestion(sq));
+					examStruct.AssignmentQuestions.Last().Index = (byte)(examStruct.AssignmentQuestions.Count());
+				});
+			}
+
+			return examStruct;
+		}
+
+
+		public static List<string> ParseOptionsFromText(this string optionsText)
+		{
+			return optionsText.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.None)
+				.Where(line => !string.IsNullOrWhiteSpace(line)).ToList();
+		}
+
+		private static QuestionDto ParseGroupToQuestion(MajorQuestionGroup qg, bool subQ = true)
+		{
+			var dq = new QuestionDto();
+			dq.Title = qg.Title + Environment.NewLine + qg.Descript;
+
+			if (subQ) dq.GroupState = QuestionGroupState.Subquestion;
+			else dq.GroupState = QuestionGroupState.Group;
+
+			qg.SubQuestions?.ForEach(ssq =>
+			{
+				dq.ChildrenQuestion.Add(ParseQuestion(ssq));
+			});
+
+			qg.SubQuestionGroups?.ForEach(sqg =>
+			{
+				dq.ChildrenQuestion.Add(ParseGroupToQuestion(sqg));
+			});
+
+			return dq;
+		}
+
+		private static AssignmentQuestionDto ParseGroupToAssignmentQuestion(MajorQuestionGroup qg, bool subQ = true)
+		{
+			var aq = new AssignmentQuestionDto();
+			aq.Score = qg.Score;
+
+			qg.SubQuestions?.ForEach(ssq =>
+			{
+				aq.Question.ChildrenQuestion.Add(ParseQuestion(ssq));
+				aq.Question.ChildrenQuestion.Last().Index = (byte)aq.Question.ChildrenQuestion.Count;
+			});
+
+			qg.SubQuestionGroups?.ForEach(sqg =>
+			{
+				aq.Question.ChildrenQuestion.Add(ParseGroupToQuestion(sqg));
+				aq.Question.ChildrenQuestion.Last().Index = (byte)aq.Question.ChildrenQuestion.Count;
+			});
+
+			return aq;
+		}
+
+
+		private static AssignmentQuestionDto ParseAssignmentQuestion(PaperQuestion sq)
+		{
+			var aq = new AssignmentQuestionDto();
+			aq.Score = sq.Score;
+
+			aq.Question = ParseQuestion(sq);
+
+			sq.SubQuestions?.ForEach(ssq =>
+			{
+
+				aq.Question.ChildrenQuestion.Add(ParseQuestion(ssq));
+				aq.Question.ChildrenQuestion.Last().Index = (byte)aq.Question.ChildrenQuestion.Count;
+
+			});
+
+			return aq;
+		}
+
+		private static QuestionDto ParseQuestion(PaperQuestion sq)
+		{
+			var dq = new QuestionDto();
+			dq.Title = sq.Stem;
+			dq.Options = string.Join(Environment.NewLine, sq.Options.Select(opt => $"{opt.Label} {opt.Text}"));
+			dq.Score = sq.Score;
+
+
+			sq.SubQuestions?.ForEach(ssq =>
+			{
+				dq.ChildrenQuestion.Add(ParseQuestion(ssq));
+				dq.ChildrenQuestion.Last().Index = (byte)dq.ChildrenQuestion.Count;
+			});
+
+			return dq;
+		}
+
 		private static void ParseMajorQuestionGroup(MajorQuestionGroup qg, QuestionGroupDto qgd, bool isParentGroupValidChain)
 		{
 			qgd.Title = qg.Title;
@@ -86,12 +192,10 @@ namespace TechHelper.Client.Exam
 				});
 			}
 
-			// 处理 MajorQuestionGroup 下的 SubQuestions
 			if (qg.SubQuestions != null)
 			{
 				qg.SubQuestions.ForEach(sq =>
 				{
-					// 如果 MajorQuestionGroup 下的 Question 包含子问题，则转为 QuestionGroupDto
 					if (sq.SubQuestions != null && sq.SubQuestions.Any())
 					{
 						var subQgd = new QuestionGroupDto
@@ -101,7 +205,6 @@ namespace TechHelper.Client.Exam
 							Score = (int)sq.Score,
 							Descript = "" // 默认为空
 						};
-						// 判断当前组是否有效：如果有描述，并且其父级链中没有任何一个组是有效组，则当前组有效
 						subQgd.ValidQuestionGroup = !string.IsNullOrEmpty(subQgd.Descript) && !nextIsParentGroupValidChain;
 
 						ParseQuestionWithSubQuestions(sq, subQgd, subQgd.ValidQuestionGroup || nextIsParentGroupValidChain);
@@ -121,7 +224,7 @@ namespace TechHelper.Client.Exam
 
 		// 解析包含子问题的 Question，将其转换为 QuestionGroupDto
 		// isParentGroupValidChain 参数表示从顶层到当前组的任一父组是否已经是“有效组”
-		private static void ParseQuestionWithSubQuestions(Question question, QuestionGroupDto qgd, bool isParentGroupValidChain)
+		private static void ParseQuestionWithSubQuestions(PaperQuestion question, QuestionGroupDto qgd, bool isParentGroupValidChain)
 		{
 			qgd.Title = question.Stem;
 			qgd.Score = (int)question.Score;
@@ -165,7 +268,7 @@ namespace TechHelper.Client.Exam
 		}
 
 		// 解析单个 Question (没有子问题) 为 SubQuestionDto
-		private static void ParseSingleQuestion(Question question, SubQuestionDto subQd, bool validQ)
+		private static void ParseSingleQuestion(PaperQuestion question, SubQuestionDto subQd, bool validQ)
 		{
 			subQd.Stem = question.Stem;
 			subQd.Score = (int)question.Score;
@@ -187,7 +290,7 @@ namespace TechHelper.Client.Exam
 
 		public static void SeqIndex(this ExamDto dto)
 		{
-			dto.QuestionGroups.SeqQGroupIndex();
+			dto.ExamStruct.SeqQGroupIndex();
 		}
 
 
diff --git a/TechHelper.Client/Exam/ExamParse.cs b/TechHelper.Client/Exam/ExamParse.cs
index a69c391..9aa9e1d 100644
--- a/TechHelper.Client/Exam/ExamParse.cs
+++ b/TechHelper.Client/Exam/ExamParse.cs
@@ -51,7 +51,7 @@ namespace TechHelper.Client.Exam
 		public string Description { get; set; } = "未识别试卷描述";
 		public string SubjectArea { get; set; } = "试卷类别";
 		public List<MajorQuestionGroup> QuestionGroups { get; set; } = new List<MajorQuestionGroup>();
-		public List<Question> TopLevelQuestions { get; set; } = new List<Question>();
+		public List<PaperQuestion> TopLevelQuestions { get; set; } = new List<PaperQuestion>();
 		public List<ParseError> Errors { get; set; } = new List<ParseError>();
 	}
 
@@ -61,17 +61,18 @@ namespace TechHelper.Client.Exam
 		public string Descript { get; set; } = string.Empty;
 		public float Score { get; set; }
 		public List<MajorQuestionGroup> SubQuestionGroups { get; set; } = new List<MajorQuestionGroup>();
-		public List<Question> SubQuestions { get; set; } = new List<Question>();
+		public List<PaperQuestion> SubQuestions { get; set; } = new List<PaperQuestion>();
 		public int Priority { get; set; }
+		public bool bGroup { get; set; } = true;
 	}
 
-	public class Question
+	public class PaperQuestion
 	{
 		public string Number { get; set; } = string.Empty;
 		public string Stem { get; set; } = string.Empty;
 		public float Score { get; set; }
 		public List<Option> Options { get; set; } = new List<Option>();
-		public List<Question> SubQuestions { get; set; } = new List<Question>();
+		public List<PaperQuestion> SubQuestions { get; set; } = new List<PaperQuestion>();
 		public string SampleAnswer { get; set; } = string.Empty;
 		public string QuestionType { get; set; } = string.Empty;
 		public int Priority { get; set; }
@@ -120,17 +121,17 @@ namespace TechHelper.Client.Exam
 		public ExamParserConfig()
 		{
 			MajorQuestionGroupPatterns.Add(new RegexPatternConfig(@"^([一二三四五六七八九十]+)[、\.]\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 1));
-			MajorQuestionGroupPatterns.Add(new RegexPatternConfig(@"^\(([一二三四五六七八九十]{1,2}|十[一二三四五六七八九])\)\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 2));
+			QuestionPatterns.Add(new RegexPatternConfig(@"^\(([一二三四五六七八九十]{1,2}|十[一二三四五六七八九])\)\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 1));
 
 
 			// 模式 1: "1. 这是一个题目 (5分)" 或 "1. 这是一个题目"
-			QuestionPatterns.Add(new RegexPatternConfig(@"^(\d+)\.\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 1));
+			QuestionPatterns.Add(new RegexPatternConfig(@"^(\d+)\.\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 2));
 
 			// 模式 2: "(1) 这是一个子题目 (3分)" 或 "(1) 这是一个子题目"
-			QuestionPatterns.Add(new RegexPatternConfig(@"^\((\d+)\)\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 2));
+			QuestionPatterns.Add(new RegexPatternConfig(@"^\((\d+)\)\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 3));
 
 			// 模式 3: "① 这是一个更深层次的子题目 (2分)" 或 "① 这是一个更深层次的子题目"
-			QuestionPatterns.Add(new RegexPatternConfig(@"^[①②③④⑤⑥⑦⑧⑨⑩]+\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 3));
+			QuestionPatterns.Add(new RegexPatternConfig(@"^[①②③④⑤⑥⑦⑧⑨⑩]+\s*(.+?)(?:\s*\(((\d+(?:\.\d+)?))\s*分\))?\s*$", 4));
 
 
 			OptionPatterns.Add(new RegexPatternConfig(@"([A-Z]\.)\s*(.*?)(?=[A-Z]\.|$)", 1)); // 大写字母选项
@@ -251,6 +252,23 @@ namespace TechHelper.Client.Exam
 			_config = config ?? throw new ArgumentNullException(nameof(config), "ExamParserConfig cannot be null.");
 		}
 
+
+
+		/// 
+		/// 一.基础
+		///		1.听写
+		///		2.阅读
+		///	二.提升
+		///		1.阅读
+		///			(1).选择
+		///			(2).填空
+		/// 三.写
+		///		(一)课文
+		///		
+		///
+		///
+
+
 		/// <summary>
 		/// Builds the ExamPaper structure from raw text and potential matches.
 		/// Collects and returns parsing errors encountered during the process.
@@ -260,7 +278,7 @@ namespace TechHelper.Client.Exam
 		/// <returns>An ExamPaper object containing the parsed structure and a list of errors.</returns>
 		/// <exception cref="ArgumentException">Thrown if fullExamText is null or empty.</exception>
 		/// <exception cref="ArgumentNullException">Thrown if allPotentialMatches is null.</exception>
-		public ExamPaper BuildExamPaper(string fullExamText, List<PotentialMatch> allPotentialMatches)
+		public ExamPaper BuildExam(string fullExamText, List<PotentialMatch> allPotentialMatches)
 		{
 			// 核心输入验证仍然是必要的，因为这些错误是无法恢复的
 			if (string.IsNullOrWhiteSpace(fullExamText))
@@ -289,8 +307,8 @@ namespace TechHelper.Client.Exam
 			var majorQGStack = new Stack<MajorQuestionGroup>();
 			MajorQuestionGroup currentMajorQG = null;
 
-			var questionStack = new Stack<Question>();
-			Question currentQuestion = null;
+			var questionStack = new Stack<PaperQuestion>();
+			PaperQuestion currentQuestion = null;
 
 			int currentContentStart = 0;
 
@@ -388,6 +406,7 @@ namespace TechHelper.Client.Exam
 								Title = pm.RegexMatch.Groups[2].Value.Trim(), // 标题是 Group 2
 								Score = score,
 								Priority = pm.PatternConfig.Priority,
+								bGroup = true
 							};
 
 							if (majorQGStack.Any())
@@ -446,7 +465,7 @@ namespace TechHelper.Client.Exam
 								}
 							}
 
-							Question newQuestion = new Question
+							PaperQuestion newQuestion = new PaperQuestion
 							{
 								Number = pm.RegexMatch.Groups[1].Value.Trim(),
 								Stem = pm.RegexMatch.Groups[2].Value.Trim(),
@@ -618,7 +637,7 @@ namespace TechHelper.Client.Exam
 		/// Processes the content of a Question, mainly for parsing Options and identifying unstructured text.
 		/// Logs errors to the provided error list instead of throwing.
 		/// </summary>
-		private void ProcessQuestionContent(Question question, string contentText, List<PotentialMatch> potentialMatchesInScope, List<ParseError> errors)
+		private void ProcessQuestionContent(PaperQuestion question, string contentText, List<PotentialMatch> potentialMatchesInScope, List<ParseError> errors)
 		{
 			// 参数验证，这些是内部方法的契约，如果违反则直接抛出，因为这意味着调用者有错
 			if (question == null) throw new ArgumentNullException(nameof(question), "Question cannot be null in ProcessQuestionContent.");
@@ -674,8 +693,10 @@ namespace TechHelper.Client.Exam
 							question.Options.Add(newOption);
 							lastOptionEndIndex = pm.EndIndex;
 						}
-						// TODO: If there are SubQuestion types, they can be processed similarly here.
-						// 你可以在此处添加对子问题的处理逻辑，同样需要小心处理其内容和嵌套。
+						else
+						{
+							question.Stem += contentText;
+						}
 					}
 					catch (Exception innerEx)
 					{
@@ -734,7 +755,7 @@ namespace TechHelper.Client.Exam
 			// 2. 构建：根据扫描结果和原始文本，线性遍历并构建层级结构
 			// BuildExamPaper 现在会返回一个包含错误列表的 ExamPaper 对象
 			// 外部不再需要捕获内部解析异常，只需检查 ExamPaper.Errors 列表
-			return _builder.BuildExamPaper(examPaperText, allPotentialMatches);
+			return _builder.BuildExam(examPaperText, allPotentialMatches);
 		}
 	}
 }
\ No newline at end of file
diff --git a/TechHelper.Client/Exam/ExamStruct.cs b/TechHelper.Client/Exam/ExamStruct.cs
index f335709..7ecdd33 100644
--- a/TechHelper.Client/Exam/ExamStruct.cs
+++ b/TechHelper.Client/Exam/ExamStruct.cs
@@ -52,7 +52,7 @@ namespace TechHelper.Client.Exam
 				Title = dto.AssignmentTitle 
 			};
 
-			GetSeqRecursive(dto.QuestionGroups, null, examStruct.Questions);
+			GetSeqRecursive(dto.ExamStruct, null, examStruct.Questions);
 
 			return examStruct;
 		}
diff --git a/TechHelper.Client/Pages/Exam/ExamCheck.razor b/TechHelper.Client/Pages/Exam/ExamCheck.razor
index 92fd91e..d4b7c90 100644
--- a/TechHelper.Client/Pages/Exam/ExamCheck.razor
+++ b/TechHelper.Client/Pages/Exam/ExamCheck.razor
@@ -1,5 +1,6 @@
 @using Entities.DTO
 @using TechHelper.Client.Exam
+@using TechHelper.Client.Services
 @page "/exam/check/{ExamID}"
 
 
diff --git a/TechHelper.Client/Pages/Exam/ExamCreate.razor b/TechHelper.Client/Pages/Exam/ExamCreate.razor
index 92222c4..9b14215 100644
--- a/TechHelper.Client/Pages/Exam/ExamCreate.razor
+++ b/TechHelper.Client/Pages/Exam/ExamCreate.razor
@@ -1,4 +1,5 @@
 @page "/exam/create"
+@using TechHelper.Client.Services
 @using Blazored.TextEditor
 @using Entities.DTO
 @using TechHelper.Client.Exam
@@ -82,7 +83,7 @@
 	}
 	private BlazoredTextEditor _textEditor = new BlazoredTextEditor();
 	private ExamPaper _parsedExam = new ExamPaper();
-	private ExamDto ExamContent = new ExamDto();
+	private AssignmentDto ExamContent = new AssignmentDto();
 
 	private ExamParserConfig _examParserConfig { get; set; } = new ExamParserConfig();
 
@@ -101,7 +102,7 @@
 				Snackbar.Add("试卷解析成功。", Severity.Success);
 				Snackbar.Add($"{_parsedExam.Errors}。", Severity.Success);
 				ExamContent = _parsedExam.ConvertToExamDTO();
-				ExamContent.SeqIndex();
+				// ExamContent.SeqIndex();
 			}
 			catch (Exception ex)
 			{
@@ -125,7 +126,6 @@
 
 	public async Task Publish()
 	{
-		ExamContent.CreaterEmail = authenticationStateTask.Result.User.Identity.Name;
 		var apiRespon = await examService.SaveParsedExam(ExamContent);
 		Snackbar.Add(apiRespon.Message);
 	}
diff --git a/TechHelper.Client/Pages/Exam/ExamEdit.razor b/TechHelper.Client/Pages/Exam/ExamEdit.razor
index 79bf546..970bafa 100644
--- a/TechHelper.Client/Pages/Exam/ExamEdit.razor
+++ b/TechHelper.Client/Pages/Exam/ExamEdit.razor
@@ -1,5 +1,7 @@
 @page "/exam/edit/{ExamId}"
 @using Entities.DTO
+@using TechHelper.Client.Services
+@using Entities.DTO
 @using TechHelper.Client.Exam
 
 <ExamView ParsedExam="@ExamDto"/>
@@ -17,7 +19,7 @@
 	[Inject]
 	private ISnackbar Snackbar { get; set; }
 
-	private ExamDto ExamDto { get; set; }
+	private AssignmentDto ExamDto { get; set; }
 
 	protected override async Task OnInitializedAsync()
 	{
@@ -27,8 +29,8 @@
 			Console.WriteLine($"ExamId 字符串成功解析为 Guid: {parsedExamId}");
 			try
 			{
-				var result = await ExamService.GetExam(parsedExamId);
-				if (result.Status) ExamDto = result.Result as ExamDto ?? new ExamDto();
+				// var result = await ExamService.GetExam(parsedExamId);
+				// if (result.Status) ExamDto = result.Result as ExamDto ?? new ExamDto();
 			}
 			catch (Exception ex)
 			{
diff --git a/TechHelper.Client/Pages/Exam/ExamGroupView.razor b/TechHelper.Client/Pages/Exam/ExamGroupView.razor
index e6b2b65..0314daa 100644
--- a/TechHelper.Client/Pages/Exam/ExamGroupView.razor
+++ b/TechHelper.Client/Pages/Exam/ExamGroupView.razor
@@ -4,41 +4,29 @@
 
 <MudPaper Elevation=@Elevation Class=@Class>
 
-	@foreach (var majorQG in MajorQGList)
-	{
-		<MudStack Row="true">
-			<MudText Typo="Typo.h6">@majorQG.Title</MudText>
-			@if (majorQG.Score > 0)
+	<MudStack Row="true">
+		<MudText Typo="Typo.h6">@ExamStruct.Title</MudText>
+		@if (ExamStruct.Score > 0)
 			{
-				<MudText Typo="Typo.body2"><b>总分:</b> @majorQG.Score 分</MudText>
+			<MudText Typo="Typo.body2"><b>总分:</b> @ExamStruct.Score 分</MudText>
 			}
 		</MudStack>
 
+	@foreach (var childStruct in ExamStruct.ChildrenGroups)
+	{
+		<ExamGroupView ExamStruct="childStruct"/>
+	}
 
-		@if (!string.IsNullOrWhiteSpace(majorQG.Descript))
-		{
-			<MudText Typo="Typo.body2">@((MarkupString)majorQG.Descript.Replace("\n", "<br />"))</MudText>
-		}
-
-		@if (majorQG.SubQuestions.Any())
-		{
-			@foreach (var question in majorQG.SubQuestions)
-			{
-				<QuestionCard Question="question" Elevation=@Elevation Class="my-2 pa-1" />
-			}
-		}
-
-		@if (majorQG.SubQuestionGroups.Any())
-		{
-			<ExamGroupView MajorQGList="majorQG.SubQuestionGroups" Elevation="1" />
-		}
+	@foreach (var question in ExamStruct.AssignmentQuestions)
+	{
+		<QuestionCard Question="question.Question" Elevation=@Elevation Class="my-2 pa-1" />
 	}
 
 </MudPaper>
 
 @code {
 	[Parameter]
-	public List<QuestionGroupDto> MajorQGList { get; set; } = new List<QuestionGroupDto>();
+	public AssignmentStructDto ExamStruct { get; set; } = new AssignmentStructDto();
 
 	[Parameter]
 	public string Class { get; set; } = "my-2 pa-1";
diff --git a/TechHelper.Client/Pages/Exam/ExamManager.razor b/TechHelper.Client/Pages/Exam/ExamManager.razor
index 6b16783..a8c15e6 100644
--- a/TechHelper.Client/Pages/Exam/ExamManager.razor
+++ b/TechHelper.Client/Pages/Exam/ExamManager.razor
@@ -4,6 +4,8 @@
 
 
 @page "/exam/manage"
+@using Entities.DTO
+@using TechHelper.Client.Services
 @attribute [Authorize]
 
 
diff --git a/TechHelper.Client/Pages/Exam/ExamView.razor b/TechHelper.Client/Pages/Exam/ExamView.razor
index 3d4e1a9..8a25906 100644
--- a/TechHelper.Client/Pages/Exam/ExamView.razor
+++ b/TechHelper.Client/Pages/Exam/ExamView.razor
@@ -5,10 +5,10 @@
 {
 
 	<MudPaper Height="@Height" Class="@Class" Style="@Style" Width="@Width">
-		<MudText Class="d-flex justify-content-center" Typo="Typo.h6"> @ParsedExam.AssignmentTitle </MudText>
+		<MudText Class="d-flex justify-content-center" Typo="Typo.h6"> @ParsedExam.Title </MudText>
 		<MudText Typo="Typo.body1"> @ParsedExam.Description </MudText>
 
-		<ExamGroupView MajorQGList="@ParsedExam.QuestionGroups.SubQuestionGroups" Elevation="1" Class="ma-0 pa-2" />
+		<ExamGroupView ExamStruct="@ParsedExam.ExamStruct" Elevation="1" Class="ma-0 pa-2" />
 	</MudPaper>
 
 }
@@ -24,7 +24,7 @@ else
 @code {
 
 	[Parameter]
-	public ExamDto ParsedExam { get; set; } = new ExamDto();
+	public AssignmentDto ParsedExam { get; set; } = new AssignmentDto();
 	[Parameter]
 	public string Height { get; set; } = "100%";
 	[Parameter]
diff --git a/TechHelper.Client/Pages/Exam/QuestionCard.razor b/TechHelper.Client/Pages/Exam/QuestionCard.razor
index 745340b..cfc3f57 100644
--- a/TechHelper.Client/Pages/Exam/QuestionCard.razor
+++ b/TechHelper.Client/Pages/Exam/QuestionCard.razor
@@ -4,29 +4,35 @@
 <MudPaper Class=@Class Elevation=@Elevation Outlined="false">
 
 	<MudText Typo="Typo.subtitle1">
-		<b>@Question.Index</b> @((MarkupString)Question.Stem.Replace("\n", "<br />"))
+		<b>@Question.Index</b> @((MarkupString)Question.Title.Replace("\n", "<br />"))
 		@if (Question.Score > 0)
 		{
 			<MudText Typo="Typo.body2" Class="d-inline ml-2">(@Question.Score 分)</MudText>
 		}
 	</MudText>
 
-	@if (Question.Options.Any())
+	@if (Question.Options != null)
 	{
 		<div class="mt-2">
-			@foreach (var option in Question.Options)
+			@foreach (var option in Question.Options.ParseOptionsFromText())
 			{
 				var tempOption = option;
-				<p>@((MarkupString)(tempOption.Value.Replace("\n", "<br />")))</p>
+				<p>@((MarkupString)(tempOption.Replace("\n", "<br />")))</p>
 			}
 		</div>
 	}
 
+
+	@foreach(var item in Question.ChildrenQuestion)
+	{
+		<QuestionCard Question="item"/>
+
+	}
 </MudPaper>
 
 @code {
 	[Parameter]
-	public SubQuestionDto Question { get; set; } = new SubQuestionDto();
+	public QuestionDto Question { get; set; } = new QuestionDto();
 
 	[Parameter]
 	public string Class { get; set; }
diff --git a/TechHelper.Client/Program.cs b/TechHelper.Client/Program.cs
index 5e6d4fe..01b6167 100644
--- a/TechHelper.Client/Program.cs
+++ b/TechHelper.Client/Program.cs
@@ -13,7 +13,6 @@ using TechHelper.Client.Services;
 using Microsoft.Extensions.Options;
 using Microsoft.AspNetCore.Components.WebAssembly.Authentication;
 using TechHelper.Client.AI;
-using TechHelper.Client.Exam;
 using Microsoft.AspNetCore.Components;
 
 
diff --git a/TechHelper.Client/Exam/ExamService.cs b/TechHelper.Client/Services/ExamService.cs
similarity index 95%
rename from TechHelper.Client/Exam/ExamService.cs
rename to TechHelper.Client/Services/ExamService.cs
index bcf65ed..656b675 100644
--- a/TechHelper.Client/Exam/ExamService.cs
+++ b/TechHelper.Client/Services/ExamService.cs
@@ -3,9 +3,9 @@ using TechHelper.Client.AI;
 using TechHelper.Services;
 using Entities.DTO;
 using System.Net.Http.Json; // 用于 PostAsJsonAsync
-using Newtonsoft.Json; // 用于 JSON 反序列化
+using Newtonsoft.Json;
 
-namespace TechHelper.Client.Exam
+namespace TechHelper.Client.Services
 {
 	public class ExamService : IExamService
 	{
@@ -144,10 +144,10 @@ namespace TechHelper.Client.Exam
 			}
 		}
 
-		public async Task<ApiResponse> SaveParsedExam(ExamDto examDto)
+		public async Task<ApiResponse> SaveParsedExam(AssignmentDto assiDto)
 		{
 			// 直接使用注入的 _client 实例
-			var response = await _client.PostAsJsonAsync("exam/add", examDto);
+			var response = await _client.PostAsJsonAsync("exam/add", assiDto);
 
 			if (response.IsSuccessStatusCode) // 检查是否是成功的状态码，例如 200 OK, 201 Created 等
 			{
diff --git a/TechHelper.Client/Exam/IExamService.cs b/TechHelper.Client/Services/IExamService.cs
similarity index 80%
rename from TechHelper.Client/Exam/IExamService.cs
rename to TechHelper.Client/Services/IExamService.cs
index 1f20dab..7b4364c 100644
--- a/TechHelper.Client/Exam/IExamService.cs
+++ b/TechHelper.Client/Services/IExamService.cs
@@ -1,13 +1,13 @@
 using Entities.DTO;
 using TechHelper.Services;
 
-namespace TechHelper.Client.Exam
+namespace TechHelper.Client.Services
 {
 	public interface IExamService
 	{
 		public Task<ApiResponse> FormatExam(string examContent);
 		public Task<ApiResponse> DividExam(string examContent);
-		public Task<ApiResponse> SaveParsedExam(ExamDto examDto);
+		public Task<ApiResponse> SaveParsedExam(AssignmentDto assiDto);
 		public Task<ApiResponse> ParseSingleQuestionGroup(string examContent);
 		public ApiResponse ConvertToXML<T>(string xmlContent);
 
diff --git a/TechHelper.Client/TechHelper.Client.csproj b/TechHelper.Client/TechHelper.Client.csproj
index afddc5a..1631edf 100644
--- a/TechHelper.Client/TechHelper.Client.csproj
+++ b/TechHelper.Client/TechHelper.Client.csproj
@@ -22,6 +22,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="AutoMapper" Version="14.0.0" />
     <PackageReference Include="Blazor.LocalStorage.WebAssembly" Version="8.0.0" />
     <PackageReference Include="Blazored.TextEditor" Version="1.1.3" />
     <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="8.0.12" />
diff --git a/TechHelper.Server/Context/ApplicationContext.cs b/TechHelper.Server/Context/ApplicationContext.cs
index 72351b1..ea3a01c 100644
--- a/TechHelper.Server/Context/ApplicationContext.cs
+++ b/TechHelper.Server/Context/ApplicationContext.cs
@@ -3,7 +3,6 @@ using Microsoft.AspNetCore.Identity;
 using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore;
 using Entities.Contracts;
-using TechHelper.Server.Context.Configuration;
 
 namespace TechHelper.Context
 {
@@ -36,7 +35,6 @@ namespace TechHelper.Context
 			builder.ApplyConfiguration(new ClassTeacherConfiguration());
 			builder.ApplyConfiguration(new QuestionConfiguration());
 			builder.ApplyConfiguration(new SubmissionConfiguration());
-			builder.ApplyConfiguration(new QuestionGroupConfiguration());
 			builder.ApplyConfiguration(new SubmissionDetailConfiguration());
 		}
 	}
diff --git a/TechHelper.Server/Context/AutoMapperProFile.cs b/TechHelper.Server/Context/AutoMapperProFile.cs
index 226d534..57ace8c 100644
--- a/TechHelper.Server/Context/AutoMapperProFile.cs
+++ b/TechHelper.Server/Context/AutoMapperProFile.cs
@@ -36,60 +36,41 @@ namespace TechHelper.Context
 
 			CreateMap<SubQuestionDto, Question>()
 				 .ForMember(dest => dest.Id, opt => opt.Ignore())
-				 .ForMember(dest => dest.QuestionText, opt => opt.MapFrom(src => src.Stem))
-				 .ForMember(dest => dest.CorrectAnswer, opt => opt.MapFrom(src => src.SampleAnswer))
-				 .ForMember(dest => dest.QuestionType, opt => opt.MapFrom(src => EnumMappingHelpers.ParseEnumSafe(src.QuestionType, QuestionType.Unknown)))
+				 .ForMember(dest => dest.Title, opt => opt.MapFrom(src => src.Stem))
+				 .ForMember(dest => dest.Answer, opt => opt.MapFrom(src => src.SampleAnswer))
+				 .ForMember(dest => dest.Type, opt => opt.MapFrom(src => EnumMappingHelpers.ParseEnumSafe(src.QuestionType, QuestionType.Unknown)))
 				 .ForMember(dest => dest.DifficultyLevel, opt => opt.MapFrom(src => EnumMappingHelpers.ParseEnumSafe(src.DifficultyLevel, DifficultyLevel.easy)))
 				 .ForMember(dest => dest.SubjectArea, opt => opt.MapFrom(src => EnumMappingHelpers.ParseEnumSafe(src.DifficultyLevel, SubjectAreaEnum.Unknown)))
-				 .ForMember(dest => dest.CreatedBy, opt => opt.Ignore())
+				 .ForMember(dest => dest.CreatorId, opt => opt.Ignore())
 				 .ForMember(dest => dest.CreatedAt, opt => opt.Ignore())
 				 .ForMember(dest => dest.UpdatedAt, opt => opt.Ignore())
 				 .ForMember(dest => dest.IsDeleted, opt => opt.Ignore());
 
-			// 2. Question -> SubQuestionDto (查看时)
-			CreateMap<Question, SubQuestionDto>()
-				.ForMember(dest => dest.Stem, opt => opt.MapFrom(src => src.QuestionText))
-				.ForMember(dest => dest.Score, opt => opt.Ignore()) // Question 实体没有 Score 字段，需要从 AssignmentQuestion 获取
-				.ForMember(dest => dest.SampleAnswer, opt => opt.MapFrom(src => src.CorrectAnswer))
-				.ForMember(dest => dest.QuestionType, opt => opt.MapFrom(src => src.QuestionType.ToString()))
-				.ForMember(dest => dest.DifficultyLevel, opt => opt.MapFrom(src => src.DifficultyLevel.ToString()))
-				.ForMember(dest => dest.Options, opt => opt.Ignore()); // Options 需要单独处理
 
-			CreateMap<Assignment, ExamDto>()
-				.ForMember(dest => dest.AssignmentTitle, opt => opt.MapFrom(src => src.Title))
-				.ForMember(dest => dest.Description, opt => opt.MapFrom(src => src.Description))
-				.ForMember(dest => dest.AssignmentId, opt => opt.MapFrom(src => src.Id))
-				.ForMember(dest => dest.QuestionGroups, opt => opt.MapFrom(src =>
-																	src.AssignmentGroups.FirstOrDefault(ag => ag.ParentGroup == null)))
-				.ForMember(dest => dest.SubjectArea, opt => opt.MapFrom(src => src.SubjectArea.ToString()));
+			// =============================================================
+			// ENTITY -> DTO Mappings (用于读取/查询)
+			// =============================================================
+			CreateMap<Assignment, AssignmentDto>()
+				.ForMember(dest => dest.ExamStruct, opt => opt.MapFrom(src => src.ExamStruct));
 
-			CreateMap<AssignmentGroup, QuestionGroupDto>()
-				.ForMember(dest => dest.SubQuestionGroups, opt => opt.MapFrom(src => src.ChildAssignmentGroups))
-				.ForMember(dest => dest.SubQuestions, opt => opt.MapFrom(src => src.AssignmentQuestions));
+			CreateMap<AssignmentStruct, AssignmentStructDto>(); // 直接映射，因为成员现在对等了
 
-			CreateMap<AssignmentQuestion, SubQuestionDto>()
-				.ForMember(dest => dest.Stem, opt => opt.MapFrom(src => src.Question.QuestionText))
-				.ForMember(dest => dest.SampleAnswer, opt => opt.MapFrom(src => src.Question.CorrectAnswer))
-				.ForMember(dest => dest.QuestionType, opt => opt.MapFrom(src => src.Question.QuestionType.ToString()))
-				.ForMember(dest => dest.DifficultyLevel, opt => opt.MapFrom(src => src.Question.DifficultyLevel.ToString()));
+			// 新增！从实体到新的 DTO 的映射
+			CreateMap<AssignmentQuestion, AssignmentQuestionDto>();
 
+			CreateMap<Question, QuestionDto>();
 
+			// =================================================================
+			// DTO -> ENTITY Mappings (用于创建/更新) - 现在变得极其简单！
+			// =================================================================
+			CreateMap<AssignmentDto, Assignment>();
+			CreateMap<AssignmentStructDto, AssignmentStruct>();
 
-			CreateMap<QuestionGroupDto, AssignmentGroup>()
-				.ForMember(dest => dest.ChildAssignmentGroups, opt => opt.MapFrom(src => src.SubQuestionGroups))
-				.ForMember(dest => dest.AssignmentQuestions, opt => opt.MapFrom(src => src.SubQuestions));
+			// 新增！从新的 DTO 到实体的映射
+			CreateMap<AssignmentQuestionDto, AssignmentQuestion>();
 
-			CreateMap<SubQuestionDto, AssignmentQuestion>()
-				.ForMember(dest => dest.Question, opt => opt.MapFrom(src => src)); // 映射到嵌套的 Question 对象
+			CreateMap<QuestionDto, Question>();
 
-			CreateMap<QuestionGroupDto, QuestionGroup>()
-				.ForMember(dest => dest.ChildQuestionGroups, opt => opt.MapFrom(src => src.SubQuestionGroups))
-				.ForMember(dest => dest.Title, opt => opt.MapFrom(src => src.Title))
-				.ForMember(dest => dest.Description, opt => opt.MapFrom(src => src.Descript));
-
-
-
-			CreateMap<Assignment, ExamDto>();
 		}
 	}
 
diff --git a/TechHelper.Server/Context/Configuration/AssignmentConfiguration.cs b/TechHelper.Server/Context/Configuration/AssignmentConfiguration.cs
index 9c42011..9d159c9 100644
--- a/TechHelper.Server/Context/Configuration/AssignmentConfiguration.cs
+++ b/TechHelper.Server/Context/Configuration/AssignmentConfiguration.cs
@@ -29,10 +29,10 @@ namespace TechHelper.Context.Configuration
 				   .IsRequired()         
 				   .HasColumnName("due_date");
 
-			builder.Property(a => a.TotalPoints)
+			builder.Property(a => a.TotalQuestions)
 				   .HasColumnName("total_points"); 
 
-			builder.Property(a => a.CreatedBy)
+			builder.Property(a => a.CreatorId)
 				   .HasColumnName("created_by"); 
 
 			builder.Property(a => a.CreatedAt)
@@ -54,7 +54,7 @@ namespace TechHelper.Context.Configuration
 			// 如果 User 有一个名为 AssignmentsCreated 的导航属性，应写为 .WithMany(u => u.AssignmentsCreated)
 			builder.HasOne(a => a.Creator)
 				   .WithMany() // User 实体没有指向 Assignment 的导航属性 (或我们不知道)
-				   .HasForeignKey(a => a.CreatedBy)
+				   .HasForeignKey(a => a.CreatorId)
 				   .IsRequired(); // CreatedBy 是必填的，对应 [Required] 在外键属性上
 
 			// 关系: Assignment (一) 到 AssignmentClass (多)
diff --git a/TechHelper.Server/Context/Configuration/AssignmentGroupConfiguration.cs b/TechHelper.Server/Context/Configuration/AssignmentGroupConfiguration.cs
index 1f526ef..d8c7828 100644
--- a/TechHelper.Server/Context/Configuration/AssignmentGroupConfiguration.cs
+++ b/TechHelper.Server/Context/Configuration/AssignmentGroupConfiguration.cs
@@ -4,9 +4,9 @@ using Microsoft.EntityFrameworkCore;
 
 namespace TechHelper.Context.Configuration
 {
-	public class AssignmentGroupConfiguration : IEntityTypeConfiguration<AssignmentGroup>
+	public class AssignmentGroupConfiguration : IEntityTypeConfiguration<AssignmentStruct>
 	{
-		public void Configure(EntityTypeBuilder<AssignmentGroup> builder)
+		public void Configure(EntityTypeBuilder<AssignmentStruct> builder)
 		{
 			// 1. 设置表名
 			// 将此实体映射到数据库中名为 "assignment_detail" 的表。
@@ -34,23 +34,23 @@ namespace TechHelper.Context.Configuration
 				.HasMaxLength(65535); // 对应 MaxLength(65535)
 
 			// 配置 Descript 属性对应的数据库列名为 "descript"，并设置最大长度。
-			builder.Property(ag => ag.Descript)
+			builder.Property(ag => ag.Description)
 				.HasColumnName("descript")
 				.HasMaxLength(65535); // 对应 MaxLength(65535)
 
 			// 配置 TotalPoints 属性对应的数据库列名为 "total_points"。
 			// TotalPoints 是 decimal? 类型，默认就是可选的，无需 IsRequired(false)。
-			builder.Property(ag => ag.TotalPoints)
+			builder.Property(ag => ag.Score)
 				.HasColumnName("total_points");
 
 			// 配置 Number 属性对应的数据库列名为 "number"。
-			builder.Property(ag => ag.Number)
+			builder.Property(ag => ag.Index)
 				.HasColumnName("number")
 				.IsRequired(); // byte 默认非空，显式 IsRequired 增加可读性。
 
 			// 配置 ParentGroup 属性对应的数据库列名为 "sub_group"。
 			// ParentGroup 是 Guid? 类型，默认就是可选的，无需 IsRequired(false)。
-			builder.Property(ag => ag.ParentGroup)
+			builder.Property(ag => ag.ParentStructId)
 				.HasColumnName("parent_group")
 				.IsRequired(false);
 
@@ -64,16 +64,16 @@ namespace TechHelper.Context.Configuration
 			// 配置 AssignmentGroup 到 Assignment 的多对一关系。
 			// 一个 AssignmentGroup 记录属于一个 Assignment。
 			builder.HasOne(ag => ag.Assignment) // 当前 AssignmentGroup 有一个 Assignment
-				.WithMany(a => a.AssignmentGroups) // 该 Assignment 可以有多个 AssignmentGroup 记录
-				.HasForeignKey(ag => ag.AssignmentId) // 通过 AssignmentId 建立外键
-				.OnDelete(DeleteBehavior.Cascade); // 当关联的 Assignment 被删除时，其所有相关的 AssignmentGroup 记录也级联删除。
+				.WithOne(a => a.ExamStruct) // 该 Assignment 可以有多个 AssignmentGroup 记录
+				.HasForeignKey<AssignmentStruct>(ag => ag.AssignmentId); // 通过 AssignmentId 建立外键
+
 
 			// 配置 AssignmentGroup 到 AssignmentGroup 的自引用关系（父子关系）。
 			// 一个 AssignmentGroup 可以有一个父 AssignmentGroup (SubAssignmentGroup)。
 			// 假设父 AssignmentGroup 实体中有一个名为 ChildAssignmentGroups 的集合属性来表示它所包含的所有子组。
-			builder.HasOne(ag => ag.ParentAssignmentGroup) // 当前 AssignmentGroup 有一个父 AssignmentGroup
-				.WithMany(parentAg => parentAg.ChildAssignmentGroups) // 该父 AssignmentGroup 可以有多个子 AssignmentGroup
-				.HasForeignKey(ag => ag.ParentGroup) // 通过 SubGroup 建立外键
+			builder.HasOne(ag => ag.ParentStruct) // 当前 AssignmentGroup 有一个父 AssignmentGroup
+				.WithMany(parentAg => parentAg.ChildrenGroups) // 该父 AssignmentGroup 可以有多个子 AssignmentGroup
+				.HasForeignKey(ag => ag.ParentStructId) // 通过 SubGroup 建立外键
 				.IsRequired(false) // SubGroup 是可空的 (Guid?)，所以这个关系是可选的。
 				.OnDelete(DeleteBehavior.SetNull); // 当父 AssignmentGroup 被删除时，其子 AssignmentGroup 的 SubGroup 外键将被设置为 NULL。
 												   // 如果你希望父组被删除时子组不能脱离父组（即不允许父组被删除），
diff --git a/TechHelper.Server/Context/Configuration/AssignmentQuestionConfiguration.cs b/TechHelper.Server/Context/Configuration/AssignmentQuestionConfiguration.cs
index c9d7a46..93413f3 100644
--- a/TechHelper.Server/Context/Configuration/AssignmentQuestionConfiguration.cs
+++ b/TechHelper.Server/Context/Configuration/AssignmentQuestionConfiguration.cs
@@ -25,12 +25,8 @@ namespace TechHelper.Context.Configuration
 				.HasColumnName("question_id");
 
 
-			builder.Property(aq => aq.QuestionGroupId)
-				.HasColumnName("question_group_id"); 
-
-
 			// 配置 QuestionNumber 列
-			builder.Property(aq => aq.QuestionNumber)
+			builder.Property(aq => aq.Index)
 				.HasColumnName("question_number")
 				.IsRequired(); // uint 类型默认非空
 
@@ -44,15 +40,10 @@ namespace TechHelper.Context.Configuration
 
 			// 配置 AssignmentGroupId 列
 			// 该列在数据库中名为 "detail_id"
-			builder.Property(aq => aq.AssignmentGroupId)
+			builder.Property(aq => aq.AssignmentStructId)
 				.HasColumnName("group_id")
 				.IsRequired();
 
-
-			builder.Property(aq => aq.IsGroup)
-			.HasColumnName("is_group") // 修正为一致的列名
-			.IsRequired(); // IsGroup 应该是必需的
-						   // 配置 IsDeleted 列
 			builder.Property(aq => aq.IsDeleted)
 				.HasColumnName("deleted")
 				.HasDefaultValue(false); // 适用于软删除策略
@@ -69,12 +60,6 @@ namespace TechHelper.Context.Configuration
 				.HasForeignKey(aq => aq.QuestionId)       // 外键是 AssignmentQuestion.QuestionId
 				.OnDelete(DeleteBehavior.Cascade);        // 当 Question 被删除时，相关的 AssignmentQuestion 也级联删除。
 
-			builder.HasOne(aq => aq.QuestionGroup)
-			.WithMany(qg => qg.AssignmentQuestions) 
-			.HasForeignKey(aq => aq.QuestionGroupId)
-			.OnDelete(DeleteBehavior.SetNull);
-
-
 			// ---
 			// 配置 AssignmentQuestion 到 AssignmentGroup 的关系 (多对一)
 			// 一个 AssignmentQuestion 属于一个 AssignmentGroup。
@@ -82,9 +67,9 @@ namespace TechHelper.Context.Configuration
 			// 你的 `AssignmentQuestion` 类现在有了 `public AssignmentGroup AssignmentGroup { get; set; }`
 			// 这是一个非常好的改进，它与 `AssignmentGroupId` 外键完美匹配。
 			// 假设 `AssignmentGroup` 实体中有一个名为 `AssignmentQuestions` 的 `ICollection<AssignmentQuestion>` 集合属性。
-			builder.HasOne(aq => aq.AssignmentGroup)        // 当前 AssignmentQuestion 有一个 AssignmentGroup
+			builder.HasOne(aq => aq.AssignmentStruct)        // 当前 AssignmentQuestion 有一个 AssignmentGroup
 				.WithMany(ag => ag.AssignmentQuestions)     // 那个 AssignmentGroup 可以有多个 AssignmentQuestion
-				.HasForeignKey(aq => aq.AssignmentGroupId)  // 外键是 AssignmentQuestion.AssignmentGroupId (列名 detail_id)
+				.HasForeignKey(aq => aq.AssignmentStructId)  // 外键是 AssignmentQuestion.AssignmentGroupId (列名 detail_id)
 				.OnDelete(DeleteBehavior.Cascade);          // 当 AssignmentGroup 被删除时，相关的 AssignmentQuestion 也级联删除。
 
 			// ---
diff --git a/TechHelper.Server/Context/Configuration/KeyPointConfiguration.cs b/TechHelper.Server/Context/Configuration/KeyPointConfiguration.cs
new file mode 100644
index 0000000..3ea3089
--- /dev/null
+++ b/TechHelper.Server/Context/Configuration/KeyPointConfiguration.cs
@@ -0,0 +1,17 @@
+using Entities.Contracts;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using Microsoft.EntityFrameworkCore;
+
+namespace TechHelper.Context.Configuration
+{
+	public class KeyPointConfiguration : IEntityTypeConfiguration<KeyPoint>
+	{
+		public void Configure(EntityTypeBuilder<KeyPoint> builder)
+		{
+			builder.HasOne(kp=>kp.Lesson)
+				.WithMany(l => l.KeyPoints)
+				.HasForeignKey(kp => kp.LessonID)
+				.OnDelete(DeleteBehavior.Cascade);
+}
+	}
+}
\ No newline at end of file
diff --git a/TechHelper.Server/Context/Configuration/QuestionConfiguration.cs b/TechHelper.Server/Context/Configuration/QuestionConfiguration.cs
index 0013354..f786b01 100644
--- a/TechHelper.Server/Context/Configuration/QuestionConfiguration.cs
+++ b/TechHelper.Server/Context/Configuration/QuestionConfiguration.cs
@@ -14,7 +14,8 @@ namespace TechHelper.Context.Configuration
 			// 2. 设置主键
 			builder.HasKey(q => q.Id);
 
-			builder.HasIndex(q => q.QuestionText);
+			builder.HasIndex(q => q.Title)
+				.HasPrefixLength(20);
 
 			// 3. 配置列名、必需性、长度及其他属性
 
@@ -23,44 +24,37 @@ namespace TechHelper.Context.Configuration
 				.HasColumnName("id");
 			// 对于 Guid 类型的主键，EF Core 默认由应用程序生成值，无需 ValueGeneratedOnAdd()
 
-			builder.Property(q => q.QuestionGroupId)
-				.HasColumnName("question_group_id")
-				.IsRequired(false); // 可为空，因为题目不一定属于某个题组
-
 
 			// QuestionText
-			builder.Property(q => q.QuestionText)
+			builder.Property(q => q.Title)
 				.HasColumnName("question_text")
 				.IsRequired()
 				.HasMaxLength(65535); // 对应 MaxLength(65535)
 
 			// QuestionType (枚举作为字符串存储)
-			builder.Property(q => q.QuestionType)
+			builder.Property(q => q.Type)
 				.HasColumnName("question_type")
 				.IsRequired()
-				.HasConversion<string>() // <-- 重要：将枚举存储为字符串
-				.HasMaxLength(20);       // <-- 应用最大长度
+				.HasMaxLength(20);      
 
 			// CorrectAnswer
-			builder.Property(q => q.CorrectAnswer)
+			builder.Property(q => q.Answer)
 				.HasColumnName("correct_answer")
-				.HasMaxLength(65535); // 对应 MaxLength(65535)
+				.HasMaxLength(65535);
 
 			// DifficultyLevel (枚举作为字符串存储)
 			builder.Property(q => q.DifficultyLevel)
 				.HasColumnName("difficulty_level")
-				.HasConversion<string>()  // <-- 重要：将枚举存储为字符串
-				.HasMaxLength(10);        // <-- 应用最大长度
-										  // DifficultyLevel 属性没有 [Required]，所以默认是可选的
+				.HasMaxLength(10);       
+										  
 
 			// SubjectArea
 			builder.Property(q => q.SubjectArea)
 			.HasColumnName("subject_area")
-			.HasConversion<string>()  // <--- 重要：将枚举存储为字符串
-			.HasMaxLength(100);       // <--- 应用最大长度 (从原 StringLength 继承)
+			.HasMaxLength(100);    
 
 			// CreatedBy
-			builder.Property(q => q.CreatedBy)
+			builder.Property(q => q.CreatorId)
 				.HasColumnName("created_by")
 				.IsRequired();
 
@@ -91,7 +85,7 @@ namespace TechHelper.Context.Configuration
 			// 假设 `User` 实体中有一个名为 `CreatedQuestions` 的 `ICollection<Question>` 集合属性。
 			builder.HasOne(q => q.Creator)             // 当前 Question 有一个 Creator
 				.WithMany(u => u.CreatedQuestions)     // 那个 Creator 可以创建多个 Question
-				.HasForeignKey(q => q.CreatedBy)       // 外键是 Question.CreatedBy
+				.HasForeignKey(q => q.CreatorId)       // 外键是 Question.CreatedBy
 				.OnDelete(DeleteBehavior.Restrict);    // 当 User (Creator) 被删除时，如果还有他/她创建的 Question，则会阻止删除。
 													   // 由于 CreatedBy 是 [Required]，Prevent/Restrict 是一个安全的选择。
 
@@ -105,11 +99,24 @@ namespace TechHelper.Context.Configuration
 				.WithOne(aq => aq.Question);                // 每一个 AssignmentQuestion 都有一个 Question
 															// .HasForeignKey(aq => aq.QuestionId); // 外键的配置应在 `AssignmentQuestionConfiguration` 中进行
 
-			builder.HasOne(q => q.QuestionGroup) // Question 实体中的 QuestionGroup 导航属性
-				.WithMany(qg => qg.Questions) // QuestionGroup 实体中的 Questions 集合
-				.HasForeignKey(q => q.QuestionGroupId) // Question 实体中的 QuestionGroupId 外键
-				.IsRequired(false) // QuestionGroupId 在 Question 实体中是可空的
-				.OnDelete(DeleteBehavior.SetNull); // 如果 QuestionGroup 被删除，关联的 Question 的外键设置为 NULL
+
+			builder.HasOne(q => q.KeyPoint)
+				.WithMany(kp => kp.Questions)
+				.HasForeignKey(q => q.KeyPointId)
+				.OnDelete(DeleteBehavior.SetNull);
+
+			builder.HasOne(q => q.Lesson)
+				.WithMany(kp => kp.Questions)
+				.IsRequired(false)
+				.HasForeignKey(q => q.LessonId)
+				.OnDelete(DeleteBehavior.SetNull);
+
+			builder.HasOne(q => q.ParentQuestion)
+				.WithMany(pq => pq.ChildrenQuestion)
+				.IsRequired(false)
+				.HasForeignKey(q => q.ParentQuestionId)
+				.OnDelete(DeleteBehavior.SetNull);
+
 		}
 	}
 }
diff --git a/TechHelper.Server/Context/Configuration/QuestionGroupConfiguration.cs b/TechHelper.Server/Context/Configuration/QuestionGroupConfiguration.cs
deleted file mode 100644
index 209abd9..0000000
--- a/TechHelper.Server/Context/Configuration/QuestionGroupConfiguration.cs
+++ /dev/null
@@ -1,111 +0,0 @@
-using Microsoft.EntityFrameworkCore.Metadata.Builders;
-using Microsoft.EntityFrameworkCore;
-using Entities.Contracts;
-
-namespace TechHelper.Server.Context.Configuration
-{
-	public class QuestionGroupConfiguration : IEntityTypeConfiguration<QuestionGroup>
-	{
-		public void Configure(EntityTypeBuilder<QuestionGroup> builder)
-		{
-			// 1. 设置表名
-			builder.ToTable("question_groups");
-
-			// 2. 设置主键
-			builder.HasKey(qg => qg.Id);
-
-			// 3. 配置列属性
-
-			// Title 标题
-			builder.Property(qg => qg.Title)
-				.HasColumnName("title")
-				.HasMaxLength(255)
-				.IsRequired(false); // 允许为空
-
-			// Description 描述内容 (Required)
-			builder.Property(qg => qg.Description)
-				.HasColumnName("description")
-				.IsRequired()
-				.HasColumnType("longtext"); // 对应 MySQL 的 TEXT 或 LONGTEXT
-
-			// Type 类型 (例如: "ReadingComprehension", "DiagramAnalysis")
-			builder.Property(qg => qg.Type)
-				.HasColumnName("type")
-				.HasMaxLength(50)
-				.IsRequired(false); // 允许为空
-
-			// DifficultyLevel 难度级别 (枚举映射为字符串)
-			builder.Property(qg => qg.DifficultyLevel)
-				.HasColumnName("difficulty_level")
-				.HasConversion<string>() // 将枚举转换为字符串存储
-				.HasMaxLength(10);
-
-			// SubjectArea 科目领域 (枚举映射为字符串)
-			builder.Property(qg => qg.SubjectArea)
-				.HasColumnName("subject_area")
-				.HasConversion<string>(); // 将枚举转换为字符串存储
-
-			// TotalQuestions 包含题目总数
-			builder.Property(qg => qg.TotalQuestions)
-				.HasColumnName("total_questions")
-				.IsRequired();
-
-			// ParentQG 父题组 ID (外键，自引用关系)
-			builder.Property(qg => qg.ParentQG)
-				.HasColumnName("parent_question_group") // 使用你定义的列名
-				.IsRequired(false); // 可为空，因为根题组没有父级
-
-			// CreatedBy 创建者 ID (外键)
-			builder.Property(qg => qg.CreatedBy)
-				.HasColumnName("created_by")
-				.IsRequired();
-
-			// CreatedAt 创建时间
-			builder.Property(qg => qg.CreatedAt)
-				.HasColumnName("created_at")
-				.IsRequired();
-
-			// UpdatedAt 更新时间
-			builder.Property(qg => qg.UpdatedAt)
-				.HasColumnName("updated_at")
-				.IsRequired();
-
-			// IsDeleted 是否删除 (软删除)
-			builder.Property(qg => qg.IsDeleted)
-				.HasColumnName("deleted")
-				.IsRequired();
-
-			// ValidGroup 是否有效
-			builder.Property(qg => qg.ValidGroup)
-				.HasColumnName("valid_group")
-				.IsRequired();
-
-			// 4. 配置关系
-
-			// 与 User 的关系 (创建者)
-			builder.HasOne(qg => qg.Creator)
-				.WithMany()
-				.HasForeignKey(qg => qg.CreatedBy)
-				.OnDelete(DeleteBehavior.Restrict); // 阻止删除关联的 User
-
-			// 与 Question 的关系 (一对多)
-			// 一个 QuestionGroup 可以包含多个 Question
-			builder.HasMany(qg => qg.Questions)
-				.WithOne(q => q.QuestionGroup) // Question 实体中的 QuestionGroup 导航属性
-				.HasForeignKey(q => q.QuestionGroupId) // Question 实体中的 QuestionGroupId 外键
-				.IsRequired(false) // QuestionGroupId 在 Question 实体中是可空的
-				.OnDelete(DeleteBehavior.SetNull); // 如果 QuestionGroup 被删除，关联的 Question 的外键设置为 NULL
-
-			// 与自身的自引用关系 (父子题组)
-			// 一个 QuestionGroup 可以有多个 ChildQuestionGroups
-			builder.HasMany(qg => qg.ChildQuestionGroups)
-				.WithOne(childQG => childQG.ParentQuestionGroup) // 子 QuestionGroup 实体中的 ParentQuestionGroup 导航属性
-				.HasForeignKey(childQG => childQG.ParentQG) // 子 QuestionGroup 实体中的 ParentQG 外键
-				.IsRequired(false) // ParentQG 是可空的，因为根题组没有父级
-				.OnDelete(DeleteBehavior.Restrict); // 或者 SetNull, Cascade。Restrict 更安全，避免意外删除整个分支。
-													// 如果选择 SetNull，删除父组时子组的 ParentQG 会变为 NULL，它们就成了新的根组。
-													// 如果选择 Cascade，删除父组会递归删除所有子组。根据业务逻辑选择。
-													// 这里我选择了 Restrict 作为默认安全选项。
-		}
-	}
-}
diff --git a/TechHelper.Server/Context/Configuration/SubmissionConfiguration.cs b/TechHelper.Server/Context/Configuration/SubmissionConfiguration.cs
index fc8d5a3..2db8c42 100644
--- a/TechHelper.Server/Context/Configuration/SubmissionConfiguration.cs
+++ b/TechHelper.Server/Context/Configuration/SubmissionConfiguration.cs
@@ -30,18 +30,13 @@ namespace TechHelper.Context.Configuration
 				.HasColumnName("student_id")
 				.IsRequired();
 
-			// AttemptNumber
-			// 注意：如果 AttemptNumber 应该是一个递增的数字，Guid 可能不是最合适的类型。
-			// 但根据你的定义，这里按 Guid 类型配置。
 			builder.Property(s => s.AttemptNumber)
 				.HasColumnName("attempt_number")
 				.IsRequired();
 
-			// SubmissionTime
 			builder.Property(s => s.SubmissionTime)
 				.HasColumnName("submission_time"); // 没有 [Required] 属性，所以可以是可空的
 
-			// OverallGrade
 			builder.Property(s => s.OverallGrade)
 				.HasColumnName("overall_grade")
 				.HasPrecision(5, 2); // 应用精度设置
@@ -51,59 +46,45 @@ namespace TechHelper.Context.Configuration
 				.HasColumnName("overall_feedback");
 
 			// GradedBy (现为 Guid? 类型)
-			builder.Property(s => s.GradedBy)
-				.HasColumnName("graded_by"); // 作为可空外键，不需要 IsRequired()
+			builder.Property(s => s.GraderId)
+				.HasColumnName("graded_by"); 
+
 
-			// GradedAt
 			builder.Property(s => s.GradedAt)
 				.HasColumnName("graded_at");
 
-			// IsDeleted
+
 			builder.Property(s => s.IsDeleted)
 				.HasColumnName("deleted")
 				.HasDefaultValue(false);
 
-			// Status (枚举作为字符串存储)
 			builder.Property(s => s.Status)
 				.HasColumnName("status")
 				.IsRequired()
-				.HasConversion<string>() // <--- 重要：将枚举存储为字符串
-				.HasMaxLength(15);       // <--- 应用最大长度
+				.HasMaxLength(15);     
+
+
 
-			// 4. 配置导航属性和外键关系
 
-			// ---
-			// 配置 Submission 到 Assignment 的关系 (多对一)
-			// 一个 Submission 属于一个 Assignment。
 			builder.HasOne(s => s.Assignment)         // 当前 Submission 有一个 Assignment
 				.WithMany(a => a.Submissions)         // 那个 Assignment 可以有多个 Submission
 				.HasForeignKey(s => s.AssignmentId)   // 外键是 Submission.AssignmentId
 				.OnDelete(DeleteBehavior.Cascade);    // 当 Assignment 被删除时，相关的 Submission 也级联删除。
 
-			// ---
-			// 配置 Submission 到 User (Student) 的关系 (多对一)
-			// 一个 Submission 由一个 User (Student) 提交。
+
 			builder.HasOne(s => s.Student)             // 当前 Submission 有一个 Student (User)
 				.WithMany(u => u.SubmissionsAsStudent) // 那个 User (Student) 可以有多个 Submission
 				.HasForeignKey(s => s.StudentId)       // 外键是 Submission.StudentId
 				.OnDelete(DeleteBehavior.Restrict);    // 当 User (Student) 被删除时，如果还有其提交的 Submission，则会阻止删除。
 
-			// ---
-			// 配置 Submission 到 User (Grader) 的关系 (多对一)
-			// 一个 Submission 可以由一个 User (Grader) 批改 (可选)。
 			builder.HasOne(s => s.Grader)              // 当前 Submission 有一个 Grader (User)，可以是空的
 				.WithMany(u => u.GradedSubmissions)    // 那个 User (Grader) 可以批改多个 Submission
-				.HasForeignKey(s => s.GradedBy)        // 外键是 Submission.GradedBy
+				.HasForeignKey(s => s.GraderId)        // 外键是 Submission.GradedBy
 				.OnDelete(DeleteBehavior.SetNull);     // 当 User (Grader) 被删除时，如果 GradedBy 是可空的，则将其设置为 NULL。
-													   // 如果 GradedBy 是不可空的，需要改为 Restrict 或 Cascade。
 
-			// ---
-			// 配置 Submission 到 SubmissionDetail 的关系 (一对多)
-			// 一个 Submission 可以有多个 SubmissionDetail。
-			// 这个关系的外键配置通常在 "多" 的一方 (`SubmissionDetail` 实体) 进行。
+
 			builder.HasMany(s => s.SubmissionDetails)   // 当前 Submission 有多个 SubmissionDetail
 				.WithOne(sd => sd.Submission);          // 每一个 SubmissionDetail 都有一个 Submission
-														// .HasForeignKey(sd => sd.SubmissionId); // 外键的配置应在 `SubmissionDetailConfiguration` 中进行
 		}
 	}
 }
diff --git a/TechHelper.Server/Context/Configuration/SubmissionDetailConfiguration.cs b/TechHelper.Server/Context/Configuration/SubmissionDetailConfiguration.cs
index 9ff5e9d..ffcf3b6 100644
--- a/TechHelper.Server/Context/Configuration/SubmissionDetailConfiguration.cs
+++ b/TechHelper.Server/Context/Configuration/SubmissionDetailConfiguration.cs
@@ -8,94 +8,65 @@ namespace TechHelper.Context.Configuration
 	{
 		public void Configure(EntityTypeBuilder<SubmissionDetail> builder)
 		{
-			// 1. 设置表名
-			// 将此实体映射到数据库中名为 "submission_details" 的表。
 			builder.ToTable("submission_details");
 
-			// 2. 设置主键
-			// 将 Id 属性设置为主键。
 			builder.HasKey(sd => sd.Id);
 
-			// 3. 配置列名、必需性、精度及其他属性
-
-			// Id 属性对应的数据库列名为 "id"。
 			builder.Property(sd => sd.Id)
 				.HasColumnName("id");
 
-			// SubmissionId 属性对应的数据库列名为 "submission_id"，并设置为必需字段。
 			builder.Property(sd => sd.SubmissionId)
 				.HasColumnName("submission_id")
 				.IsRequired();
 
-			// StudentId 属性对应的数据库列名为 "student_id"，并设置为必需字段。
-			// 此外键指向 User 实体，代表提交该详情的学生。
 			builder.Property(sd => sd.StudentId)
 				.HasColumnName("student_id")
 				.IsRequired();
 
-			// AssignmentQuestionId 属性对应的数据库列名为 "assignment_question_id"，并设置为必需字段。
 			builder.Property(sd => sd.AssignmentQuestionId)
 				.HasColumnName("assignment_question_id")
 				.IsRequired();
 
-			// StudentAnswer 属性对应的数据库列名为 "student_answer"。
 			builder.Property(sd => sd.StudentAnswer)
 				.HasColumnName("student_answer"); // string 默认可空
 
-			// IsCorrect 属性对应的数据库列名为 "is_correct"。
 			builder.Property(sd => sd.IsCorrect)
 				.HasColumnName("is_correct"); // bool? 默认可空
 
-			// PointsAwarded 属性对应的数据库列名为 "points_awarded"，并设置精度。
 			builder.Property(sd => sd.PointsAwarded)
 				.HasColumnName("points_awarded")
 				.HasPrecision(5, 2); // 应用 [Precision(5, 2)] 设置
 
-			// TeacherFeedback 属性对应的数据库列名为 "teacher_feedback"。
 			builder.Property(sd => sd.TeacherFeedback)
 				.HasColumnName("teacher_feedback"); // string 默认可空
 
-			// CreatedAt 属性对应的数据库列名为 "created_at"，设置为必需字段，并在添加时自动生成值。
 			builder.Property(sd => sd.CreatedAt)
 				.HasColumnName("created_at")
 				.IsRequired()
 				.ValueGeneratedOnAdd(); // 在实体首次保存时自动设置值
 
-			// UpdatedAt 属性对应的数据库列名为 "updated_at"，设置为必需字段，并在添加或更新时自动生成值，同时作为并发令牌。
 			builder.Property(sd => sd.UpdatedAt)
 				.HasColumnName("updated_at")
 				.IsRequired()
 				.ValueGeneratedOnAddOrUpdate() // 在实体添加或更新时自动设置值
 				.IsConcurrencyToken();       // 用作乐观并发控制，防止同时修改同一记录
 
-			// IsDeleted 属性对应的数据库列名为 "deleted"，并设置默认值为 false。
+
 			builder.Property(sd => sd.IsDeleted)
 				.HasColumnName("deleted")
-				.HasDefaultValue(false); // 常用作软删除标记
+				.HasDefaultValue(false);
 
-			// 4. 配置导航属性和外键关系
-
-			// ---
-			// 配置 SubmissionDetail 到 Submission 的关系 (多对一)
-			// 一个 SubmissionDetail 记录属于一个 Submission。
 			builder.HasOne(sd => sd.Submission)          // 当前 SubmissionDetail 有一个 Submission
 				.WithMany(s => s.SubmissionDetails)      // 那个 Submission 可以有多个 SubmissionDetail 记录
 				.HasForeignKey(sd => sd.SubmissionId)    // 外键是 SubmissionDetail.SubmissionId
 				.OnDelete(DeleteBehavior.Cascade);       // 当 Submission 被删除时，相关的 SubmissionDetail 记录也级联删除。
 
-			// ---
-			// 配置 SubmissionDetail 到 User (作为 Student) 的关系 (多对一)
-			// 一个 SubmissionDetail 记录与一个 User (提交该详情的学生) 相关联。
-			// 假设 `User` 实体中有一个名为 `SubmissionDetailsAsStudent` 的 `ICollection<SubmissionDetail>` 集合属性。
-			builder.HasOne(sd => sd.User)                     // 当前 SubmissionDetail 有一个 User (作为学生)
+			builder.HasOne(sd => sd.Student)                     // 当前 SubmissionDetail 有一个 User (作为学生)
 				.WithMany(u => u.SubmissionDetails)		
 				.HasForeignKey(sd => sd.StudentId)            // 外键是 SubmissionDetail.StudentId
 				.OnDelete(DeleteBehavior.Restrict);           // 当 User (学生) 被删除时，如果他/她还有提交详情，则会阻止删除。
 															  // 这是一个更安全的选择，以防止意外数据丢失。
 
-			// ---
-			// 配置 SubmissionDetail 到 AssignmentQuestion 的关系 (多对一)
-			// 一个 SubmissionDetail 记录对应一个 AssignmentQuestion。
 			builder.HasOne(sd => sd.AssignmentQuestion)          // 当前 SubmissionDetail 有一个 AssignmentQuestion
 				.WithMany(aq => aq.SubmissionDetails)           // 那个 AssignmentQuestion 可以有多个 SubmissionDetail 记录
 				.HasForeignKey(sd => sd.AssignmentQuestionId)   // 外键是 SubmissionDetail.AssignmentQuestionId
diff --git a/TechHelper.Server/Context/Configuration/UserConfiguration.cs b/TechHelper.Server/Context/Configuration/UserConfiguration.cs
index 6d6da53..beaaaee 100644
--- a/TechHelper.Server/Context/Configuration/UserConfiguration.cs
+++ b/TechHelper.Server/Context/Configuration/UserConfiguration.cs
@@ -8,14 +8,8 @@ namespace TechHelper.Context.Configuration
 	{
 		public void Configure(EntityTypeBuilder<User> builder)
 		{
-			// 映射到表名：如果 User 类上没有 [Table("users")]，默认是 "AspNetUsers"。
-			// 显式指定可以确保你的数据库表名和你期望的一致。
 			builder.ToTable("AspNetUsers");
 
-			// IdentityUser 的 Id 属性和其他标准属性（如 UserName, Email 等）
-			// 大多由 IdentityDbContext 自动处理，通常不需要在这里显式配置主键或默认列。
-
-			// 配置自定义属性
 			builder.Property(u => u.RefreshToken)
 				.HasColumnName("refresh_token");
 
@@ -24,11 +18,8 @@ namespace TechHelper.Context.Configuration
 
 			builder.Property(u => u.IsDeleted)
 				.HasColumnName("deleted")
-				.HasDefaultValue(false); // 软删除标记，默认 false
+				.HasDefaultValue(false); 
 
-			// 配置导航属性 (User 作为关系的“一”或“主”方)
-
-			// User 作为老师，与 ClassTeacher 的关系 (一对多)
 			builder.HasMany(u => u.TaughtClassesLink) // 一个 User (老师) 可以教授多个班级
 				.WithOne(ct => ct.Teacher)           // 一个 ClassTeacher 记录对应一个 Teacher
 				.HasForeignKey(ct => ct.TeacherId)   // 外键在 ClassTeacher.TeacherId
@@ -43,20 +34,17 @@ namespace TechHelper.Context.Configuration
 			// User 作为创建者，与 Question 的关系 (一对多)
 			builder.HasMany(u => u.CreatedQuestions) // 一个 User 可以创建多个题目
 				.WithOne(q => q.Creator)             // 一个 Question 对应一个 Creator
-				.HasForeignKey(q => q.CreatedBy)     // 外键在 Question.CreatedBy
+				.HasForeignKey(q => q.CreatorId)     // 外键在 Question.CreatedBy
 				.OnDelete(DeleteBehavior.Restrict);  // 限制删除：如果创建者有题目，则不允许删除
 
 			// User 作为创建者，与 Assignment 的关系 (一对多)
 			builder.HasMany(u => u.CreatedAssignments) // 一个 User 可以创建多个作业
 				.WithOne(a => a.Creator)               // 一个 Assignment 对应一个 Creator
-				.HasForeignKey(a => a.CreatedBy)       // 外键在 Assignment.CreatedBy
+				.HasForeignKey(a => a.CreatorId)       // 外键在 Assignment.CreatedBy
 				.OnDelete(DeleteBehavior.Restrict);    // 限制删除：如果创建者有作业，则不允许删除
 
-			// User 作为学生，与 SubmissionDetail 的关系 (一对多)
-			// 尽管 SubmissionDetail 也可以通过 Submission 间接关联到 User，
-			// 但这里提供了直接访问的导航属性，以方便直接查询学生的所有作答详情。
 			builder.HasMany(u => u.SubmissionDetails)   // 一个 User (学生) 可以有多个提交详情记录
-				.WithOne(sd => sd.User)                 // 一个 SubmissionDetail 对应一个 User (学生)
+				.WithOne(sd => sd.Student)                 // 一个 SubmissionDetail 对应一个 User (学生)
 				.HasForeignKey(sd => sd.StudentId)      // 外键在 SubmissionDetail.StudentId
 				.OnDelete(DeleteBehavior.Restrict);     // 限制删除：如果学生有提交详情，则不允许删除
 
@@ -69,7 +57,7 @@ namespace TechHelper.Context.Configuration
 			// User 作为批改者，与 Submission 的关系 (一对多)
 			builder.HasMany(u => u.GradedSubmissions)  // 一个 User (批改者) 可以批改多个提交
 				.WithOne(s => s.Grader)                // 一个 Submission 对应一个 Grader
-				.HasForeignKey(s => s.GradedBy)        // 外键在 Submission.GradedBy
+				.HasForeignKey(s => s.GraderId)        // 外键在 Submission.GradedBy
 				.OnDelete(DeleteBehavior.SetNull);     // 因为 GradedBy 是可空的，所以批改者删除时，设为 NULL
 		}
 	}
diff --git a/TechHelper.Server/Controllers/ExamController.cs b/TechHelper.Server/Controllers/ExamController.cs
index 2410bcd..3676c2b 100644
--- a/TechHelper.Server/Controllers/ExamController.cs
+++ b/TechHelper.Server/Controllers/ExamController.cs
@@ -28,9 +28,13 @@ namespace TechHelper.Server.Controllers
 
 		[HttpPost("add")]
 		public async Task<IActionResult> AddExam(
-			[FromBody] ExamDto examDto)
+			[FromBody] AssignmentDto examDto)
 		{
-			var result = await _examService.AddAsync(examDto);
+			var user = await _userManager.FindByEmailAsync(User.Identity?.Name ?? "");
+			if(user == null) return BadRequest("无效的用户");
+
+			examDto.CreatorId = user.Id;
+			var result = await _examService.CreateExamAsync(examDto);
 			if (result.Status)
 			{
 				return Ok(result);
@@ -63,7 +67,7 @@ namespace TechHelper.Server.Controllers
 
 
 
-			var result = await _examService.GetAllExamPreview(userid.Id);
+			var result = await _examService.GetAllExamPreviewsAsync(userid.Id);
 
 			if (result.Status)
 			{
diff --git a/TechHelper.Server/Migrations/20250610025810_assignment-not_required.Designer.cs b/TechHelper.Server/Migrations/20250610025810_assignment-not_required.Designer.cs
deleted file mode 100644
index 02af864..0000000
--- a/TechHelper.Server/Migrations/20250610025810_assignment-not_required.Designer.cs
+++ /dev/null
@@ -1,1091 +0,0 @@
-// <auto-generated />
-using System;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Infrastructure;
-using Microsoft.EntityFrameworkCore.Metadata;
-using Microsoft.EntityFrameworkCore.Migrations;
-using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
-using TechHelper.Context;
-
-#nullable disable
-
-namespace TechHelper.Server.Migrations
-{
-    [DbContext(typeof(ApplicationContext))]
-    [Migration("20250610025810_assignment-not_required")]
-    partial class assignmentnot_required
-    {
-        /// <inheritdoc />
-        protected override void BuildTargetModel(ModelBuilder modelBuilder)
-        {
-#pragma warning disable 612, 618
-            modelBuilder
-                .HasAnnotation("ProductVersion", "8.0.16")
-                .HasAnnotation("Relational:MaxIdentifierLength", 64);
-
-            MySqlModelBuilderExtensions.AutoIncrementColumns(modelBuilder);
-
-            modelBuilder.Entity("Entities.Contracts.Assignment", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("created_at");
-
-                    b.Property<Guid>("CreatedBy")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("created_by");
-
-                    b.Property<string>("Description")
-                        .IsRequired()
-                        .HasColumnType("longtext")
-                        .HasColumnName("description");
-
-                    b.Property<DateTime>("DueDate")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("due_date");
-
-                    b.Property<bool>("IsDeleted")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("deleted");
-
-                    b.Property<string>("SubjectArea")
-                        .IsRequired()
-                        .HasColumnType("longtext")
-                        .HasColumnName("subject_area");
-
-                    b.Property<string>("Title")
-                        .IsRequired()
-                        .HasMaxLength(255)
-                        .HasColumnType("varchar(255)")
-                        .HasColumnName("title");
-
-                    b.Property<float?>("TotalPoints")
-                        .HasColumnType("float")
-                        .HasColumnName("total_points");
-
-                    b.Property<DateTime>("UpdatedAt")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("updated_at");
-
-                    b.Property<Guid?>("UserId")
-                        .HasColumnType("char(36)");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("CreatedBy");
-
-                    b.HasIndex("UserId");
-
-                    b.ToTable("assignments", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentAttachment", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<Guid>("AssignmentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("assignment_id");
-
-                    b.Property<string>("FileName")
-                        .IsRequired()
-                        .HasMaxLength(255)
-                        .HasColumnType("varchar(255)")
-                        .HasColumnName("file_name");
-
-                    b.Property<string>("FilePath")
-                        .IsRequired()
-                        .HasMaxLength(255)
-                        .HasColumnType("varchar(255)")
-                        .HasColumnName("file_path");
-
-                    b.Property<bool>("IsDeleted")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("deleted");
-
-                    b.Property<DateTime>("UploadedAt")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("uploaded_at");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("AssignmentId");
-
-                    b.ToTable("assignment_attachments");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentClass", b =>
-                {
-                    b.Property<Guid>("AssignmentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("assignment_id")
-                        .HasColumnOrder(0);
-
-                    b.Property<Guid>("ClassId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("class_id")
-                        .HasColumnOrder(1);
-
-                    b.Property<DateTime>("AssignedAt")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("assigned_at");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.HasKey("AssignmentId", "ClassId");
-
-                    b.HasIndex("ClassId");
-
-                    b.ToTable("assignment_class", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<Guid?>("AssignmentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("assignment");
-
-                    b.Property<string>("Descript")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("descript");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<byte>("Number")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("number");
-
-                    b.Property<Guid?>("ParentGroup")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("parent_group");
-
-                    b.Property<string>("Title")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("title");
-
-                    b.Property<float?>("TotalPoints")
-                        .HasColumnType("float")
-                        .HasColumnName("total_points");
-
-                    b.Property<bool>("ValidQuestionGroup")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("valid_question_group");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("AssignmentId");
-
-                    b.HasIndex("ParentGroup");
-
-                    b.ToTable("assignment_group", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<Guid>("AssignmentGroupId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("group_id");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("created_at");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<Guid>("QuestionId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("question_id");
-
-                    b.Property<byte>("QuestionNumber")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("question_number");
-
-                    b.Property<float?>("Score")
-                        .HasColumnType("float")
-                        .HasColumnName("score");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("AssignmentGroupId");
-
-                    b.HasIndex("QuestionId");
-
-                    b.ToTable("assignment_questions", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Class", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("created_at");
-
-                    MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<DateTime>("CreatedAt"));
-
-                    b.Property<string>("Description")
-                        .HasColumnType("longtext")
-                        .HasColumnName("description");
-
-                    b.Property<byte>("Grade")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("grade");
-
-                    b.Property<Guid?>("HeadTeacherId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("head_teacher_id");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<byte>("Number")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("class");
-
-                    b.Property<DateTime>("UpdatedAt")
-                        .ValueGeneratedOnAddOrUpdate()
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("updated_at");
-
-                    MySqlPropertyBuilderExtensions.UseMySqlComputedColumn(b.Property<DateTime>("UpdatedAt"));
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("HeadTeacherId");
-
-                    b.ToTable("classes", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.ClassStudent", b =>
-                {
-                    b.Property<Guid>("ClassId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("class_id")
-                        .HasColumnOrder(0);
-
-                    b.Property<Guid>("StudentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("student_id")
-                        .HasColumnOrder(1);
-
-                    b.Property<DateTime>("EnrollmentDate")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("enrollment_date");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.HasKey("ClassId", "StudentId");
-
-                    b.HasIndex("StudentId");
-
-                    b.ToTable("class_student", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.ClassTeacher", b =>
-                {
-                    b.Property<Guid>("ClassId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("class_id");
-
-                    b.Property<Guid>("TeacherId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("teacher_id");
-
-                    b.Property<string>("SubjectTaught")
-                        .IsRequired()
-                        .HasColumnType("longtext")
-                        .HasColumnName("subject_taught");
-
-                    b.HasKey("ClassId", "TeacherId");
-
-                    b.HasIndex("TeacherId");
-
-                    b.ToTable("class_teachers", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Question", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<string>("CorrectAnswer")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("correct_answer");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("created_at");
-
-                    MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<DateTime>("CreatedAt"));
-
-                    b.Property<Guid>("CreatedBy")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("created_by");
-
-                    b.Property<string>("DifficultyLevel")
-                        .IsRequired()
-                        .HasMaxLength(10)
-                        .HasColumnType("varchar(10)")
-                        .HasColumnName("difficulty_level");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<string>("QuestionText")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("question_text");
-
-                    b.Property<string>("QuestionType")
-                        .IsRequired()
-                        .HasMaxLength(20)
-                        .HasColumnType("varchar(20)")
-                        .HasColumnName("question_type");
-
-                    b.Property<string>("SubjectArea")
-                        .IsRequired()
-                        .HasMaxLength(100)
-                        .HasColumnType("varchar(100)")
-                        .HasColumnName("subject_area");
-
-                    b.Property<DateTime>("UpdatedAt")
-                        .IsConcurrencyToken()
-                        .ValueGeneratedOnAddOrUpdate()
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("updated_at");
-
-                    b.Property<bool>("ValidQuestion")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("valid_question");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("CreatedBy");
-
-                    b.ToTable("questions", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Submission", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<Guid>("AssignmentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("assignment_id");
-
-                    b.Property<Guid>("AttemptNumber")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("attempt_number");
-
-                    b.Property<DateTime?>("GradedAt")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("graded_at");
-
-                    b.Property<Guid?>("GradedBy")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("graded_by");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<string>("OverallFeedback")
-                        .IsRequired()
-                        .HasColumnType("longtext")
-                        .HasColumnName("overall_feedback");
-
-                    b.Property<float?>("OverallGrade")
-                        .HasPrecision(5, 2)
-                        .HasColumnType("float")
-                        .HasColumnName("overall_grade");
-
-                    b.Property<string>("Status")
-                        .IsRequired()
-                        .HasMaxLength(15)
-                        .HasColumnType("varchar(15)")
-                        .HasColumnName("status");
-
-                    b.Property<Guid>("StudentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("student_id");
-
-                    b.Property<DateTime>("SubmissionTime")
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("submission_time");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("AssignmentId");
-
-                    b.HasIndex("GradedBy");
-
-                    b.HasIndex("StudentId");
-
-                    b.ToTable("submissions", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.SubmissionDetail", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<Guid>("AssignmentQuestionId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("assignment_question_id");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("created_at");
-
-                    MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<DateTime>("CreatedAt"));
-
-                    b.Property<bool?>("IsCorrect")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("is_correct");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<float?>("PointsAwarded")
-                        .HasPrecision(5, 2)
-                        .HasColumnType("float")
-                        .HasColumnName("points_awarded");
-
-                    b.Property<string>("StudentAnswer")
-                        .IsRequired()
-                        .HasColumnType("longtext")
-                        .HasColumnName("student_answer");
-
-                    b.Property<Guid>("StudentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("student_id");
-
-                    b.Property<Guid>("SubmissionId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("submission_id");
-
-                    b.Property<string>("TeacherFeedback")
-                        .IsRequired()
-                        .HasColumnType("longtext")
-                        .HasColumnName("teacher_feedback");
-
-                    b.Property<DateTime>("UpdatedAt")
-                        .IsConcurrencyToken()
-                        .ValueGeneratedOnAddOrUpdate()
-                        .HasColumnType("datetime(6)")
-                        .HasColumnName("updated_at");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("AssignmentQuestionId");
-
-                    b.HasIndex("StudentId");
-
-                    b.HasIndex("SubmissionId");
-
-                    b.ToTable("submission_details", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.User", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)");
-
-                    b.Property<int>("AccessFailedCount")
-                        .HasColumnType("int");
-
-                    b.Property<string>("Address")
-                        .HasColumnType("longtext");
-
-                    b.Property<string>("ConcurrencyStamp")
-                        .IsConcurrencyToken()
-                        .HasColumnType("longtext");
-
-                    b.Property<string>("DisplayName")
-                        .HasColumnType("longtext");
-
-                    b.Property<string>("Email")
-                        .HasMaxLength(256)
-                        .HasColumnType("varchar(256)");
-
-                    b.Property<bool>("EmailConfirmed")
-                        .HasColumnType("tinyint(1)");
-
-                    b.Property<bool>("IsDeleted")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("deleted");
-
-                    b.Property<bool>("LockoutEnabled")
-                        .HasColumnType("tinyint(1)");
-
-                    b.Property<DateTimeOffset?>("LockoutEnd")
-                        .HasColumnType("datetime(6)");
-
-                    b.Property<string>("NormalizedEmail")
-                        .HasMaxLength(256)
-                        .HasColumnType("varchar(256)");
-
-                    b.Property<string>("NormalizedUserName")
-                        .HasMaxLength(256)
-                        .HasColumnType("varchar(256)");
-
-                    b.Property<string>("PasswordHash")
-                        .HasColumnType("longtext");
-
-                    b.Property<string>("PhoneNumber")
-                        .HasColumnType("longtext");
-
-                    b.Property<bool>("PhoneNumberConfirmed")
-                        .HasColumnType("tinyint(1)");
-
-                    b.Property<string>("RefreshToken")
-                        .HasColumnType("longtext");
-
-                    b.Property<DateTime?>("RefreshTokenExpiryTime")
-                        .HasColumnType("datetime(6)");
-
-                    b.Property<string>("SecurityStamp")
-                        .HasColumnType("longtext");
-
-                    b.Property<bool>("TwoFactorEnabled")
-                        .HasColumnType("tinyint(1)");
-
-                    b.Property<string>("UserName")
-                        .HasMaxLength(256)
-                        .HasColumnType("varchar(256)");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("NormalizedEmail")
-                        .HasDatabaseName("EmailIndex");
-
-                    b.HasIndex("NormalizedUserName")
-                        .IsUnique()
-                        .HasDatabaseName("UserNameIndex");
-
-                    b.ToTable("AspNetUsers", (string)null);
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRole<System.Guid>", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)");
-
-                    b.Property<string>("ConcurrencyStamp")
-                        .IsConcurrencyToken()
-                        .HasColumnType("longtext");
-
-                    b.Property<string>("Name")
-                        .HasMaxLength(256)
-                        .HasColumnType("varchar(256)");
-
-                    b.Property<string>("NormalizedName")
-                        .HasMaxLength(256)
-                        .HasColumnType("varchar(256)");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("NormalizedName")
-                        .IsUnique()
-                        .HasDatabaseName("RoleNameIndex");
-
-                    b.ToTable("AspNetRoles", (string)null);
-
-                    b.HasData(
-                        new
-                        {
-                            Id = new Guid("d4b41bc3-612e-49dd-aeda-6a98ea0e4e68"),
-                            Name = "Student",
-                            NormalizedName = "STUDENT"
-                        },
-                        new
-                        {
-                            Id = new Guid("b2e087e6-ea32-46c4-aeb3-09b936cd0cf4"),
-                            Name = "Teacher",
-                            NormalizedName = "TEACHER"
-                        },
-                        new
-                        {
-                            Id = new Guid("ba33e047-8354-4f2c-b8b1-1f46441c28fc"),
-                            Name = "Administrator",
-                            NormalizedName = "ADMINISTRATOR"
-                        });
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRoleClaim<System.Guid>", b =>
-                {
-                    b.Property<int>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("int");
-
-                    MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<int>("Id"));
-
-                    b.Property<string>("ClaimType")
-                        .HasColumnType("longtext");
-
-                    b.Property<string>("ClaimValue")
-                        .HasColumnType("longtext");
-
-                    b.Property<Guid>("RoleId")
-                        .HasColumnType("char(36)");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("RoleId");
-
-                    b.ToTable("AspNetRoleClaims", (string)null);
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserClaim<System.Guid>", b =>
-                {
-                    b.Property<int>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("int");
-
-                    MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<int>("Id"));
-
-                    b.Property<string>("ClaimType")
-                        .HasColumnType("longtext");
-
-                    b.Property<string>("ClaimValue")
-                        .HasColumnType("longtext");
-
-                    b.Property<Guid>("UserId")
-                        .HasColumnType("char(36)");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("UserId");
-
-                    b.ToTable("AspNetUserClaims", (string)null);
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserLogin<System.Guid>", b =>
-                {
-                    b.Property<string>("LoginProvider")
-                        .HasColumnType("varchar(255)");
-
-                    b.Property<string>("ProviderKey")
-                        .HasColumnType("varchar(255)");
-
-                    b.Property<string>("ProviderDisplayName")
-                        .HasColumnType("longtext");
-
-                    b.Property<Guid>("UserId")
-                        .HasColumnType("char(36)");
-
-                    b.HasKey("LoginProvider", "ProviderKey");
-
-                    b.HasIndex("UserId");
-
-                    b.ToTable("AspNetUserLogins", (string)null);
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserRole<System.Guid>", b =>
-                {
-                    b.Property<Guid>("UserId")
-                        .HasColumnType("char(36)");
-
-                    b.Property<Guid>("RoleId")
-                        .HasColumnType("char(36)");
-
-                    b.HasKey("UserId", "RoleId");
-
-                    b.HasIndex("RoleId");
-
-                    b.ToTable("AspNetUserRoles", (string)null);
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserToken<System.Guid>", b =>
-                {
-                    b.Property<Guid>("UserId")
-                        .HasColumnType("char(36)");
-
-                    b.Property<string>("LoginProvider")
-                        .HasColumnType("varchar(255)");
-
-                    b.Property<string>("Name")
-                        .HasColumnType("varchar(255)");
-
-                    b.Property<string>("Value")
-                        .HasColumnType("longtext");
-
-                    b.HasKey("UserId", "LoginProvider", "Name");
-
-                    b.ToTable("AspNetUserTokens", (string)null);
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Assignment", b =>
-                {
-                    b.HasOne("Entities.Contracts.User", "Creator")
-                        .WithMany()
-                        .HasForeignKey("CreatedBy")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.User", null)
-                        .WithMany("CreatedAssignments")
-                        .HasForeignKey("UserId");
-
-                    b.Navigation("Creator");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentAttachment", b =>
-                {
-                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
-                        .WithMany("AssignmentAttachments")
-                        .HasForeignKey("AssignmentId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("Assignment");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentClass", b =>
-                {
-                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
-                        .WithMany("AssignmentClasses")
-                        .HasForeignKey("AssignmentId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.Class", "Class")
-                        .WithMany("AssignmentClasses")
-                        .HasForeignKey("ClassId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("Assignment");
-
-                    b.Navigation("Class");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
-                        .WithMany("AssignmentGroups")
-                        .HasForeignKey("AssignmentId")
-                        .OnDelete(DeleteBehavior.Cascade);
-
-                    b.HasOne("Entities.Contracts.AssignmentGroup", "ParentAssignmentGroup")
-                        .WithMany("ChildAssignmentGroups")
-                        .HasForeignKey("ParentGroup")
-                        .OnDelete(DeleteBehavior.SetNull);
-
-                    b.Navigation("Assignment");
-
-                    b.Navigation("ParentAssignmentGroup");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
-                {
-                    b.HasOne("Entities.Contracts.AssignmentGroup", "AssignmentGroup")
-                        .WithMany("AssignmentQuestions")
-                        .HasForeignKey("AssignmentGroupId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.Question", "Question")
-                        .WithMany("AssignmentQuestions")
-                        .HasForeignKey("QuestionId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("AssignmentGroup");
-
-                    b.Navigation("Question");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Class", b =>
-                {
-                    b.HasOne("Entities.Contracts.User", "HeadTeacher")
-                        .WithMany()
-                        .HasForeignKey("HeadTeacherId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.Navigation("HeadTeacher");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.ClassStudent", b =>
-                {
-                    b.HasOne("Entities.Contracts.Class", "Class")
-                        .WithMany("ClassStudents")
-                        .HasForeignKey("ClassId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.User", "Student")
-                        .WithMany("EnrolledClassesLink")
-                        .HasForeignKey("StudentId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.Navigation("Class");
-
-                    b.Navigation("Student");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.ClassTeacher", b =>
-                {
-                    b.HasOne("Entities.Contracts.Class", "Class")
-                        .WithMany("ClassTeachers")
-                        .HasForeignKey("ClassId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.User", "Teacher")
-                        .WithMany("TaughtClassesLink")
-                        .HasForeignKey("TeacherId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.Navigation("Class");
-
-                    b.Navigation("Teacher");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Question", b =>
-                {
-                    b.HasOne("Entities.Contracts.User", "Creator")
-                        .WithMany("CreatedQuestions")
-                        .HasForeignKey("CreatedBy")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.Navigation("Creator");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Submission", b =>
-                {
-                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
-                        .WithMany("Submissions")
-                        .HasForeignKey("AssignmentId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.User", "Grader")
-                        .WithMany("GradedSubmissions")
-                        .HasForeignKey("GradedBy")
-                        .OnDelete(DeleteBehavior.SetNull);
-
-                    b.HasOne("Entities.Contracts.User", "Student")
-                        .WithMany("SubmissionsAsStudent")
-                        .HasForeignKey("StudentId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.Navigation("Assignment");
-
-                    b.Navigation("Grader");
-
-                    b.Navigation("Student");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.SubmissionDetail", b =>
-                {
-                    b.HasOne("Entities.Contracts.AssignmentQuestion", "AssignmentQuestion")
-                        .WithMany("SubmissionDetails")
-                        .HasForeignKey("AssignmentQuestionId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.User", "User")
-                        .WithMany("SubmissionDetails")
-                        .HasForeignKey("StudentId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.Submission", "Submission")
-                        .WithMany("SubmissionDetails")
-                        .HasForeignKey("SubmissionId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("AssignmentQuestion");
-
-                    b.Navigation("Submission");
-
-                    b.Navigation("User");
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRoleClaim<System.Guid>", b =>
-                {
-                    b.HasOne("Microsoft.AspNetCore.Identity.IdentityRole<System.Guid>", null)
-                        .WithMany()
-                        .HasForeignKey("RoleId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserClaim<System.Guid>", b =>
-                {
-                    b.HasOne("Entities.Contracts.User", null)
-                        .WithMany()
-                        .HasForeignKey("UserId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserLogin<System.Guid>", b =>
-                {
-                    b.HasOne("Entities.Contracts.User", null)
-                        .WithMany()
-                        .HasForeignKey("UserId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserRole<System.Guid>", b =>
-                {
-                    b.HasOne("Microsoft.AspNetCore.Identity.IdentityRole<System.Guid>", null)
-                        .WithMany()
-                        .HasForeignKey("RoleId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.User", null)
-                        .WithMany()
-                        .HasForeignKey("UserId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-                });
-
-            modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityUserToken<System.Guid>", b =>
-                {
-                    b.HasOne("Entities.Contracts.User", null)
-                        .WithMany()
-                        .HasForeignKey("UserId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Assignment", b =>
-                {
-                    b.Navigation("AssignmentAttachments");
-
-                    b.Navigation("AssignmentClasses");
-
-                    b.Navigation("AssignmentGroups");
-
-                    b.Navigation("Submissions");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.Navigation("AssignmentQuestions");
-
-                    b.Navigation("ChildAssignmentGroups");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
-                {
-                    b.Navigation("SubmissionDetails");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Class", b =>
-                {
-                    b.Navigation("AssignmentClasses");
-
-                    b.Navigation("ClassStudents");
-
-                    b.Navigation("ClassTeachers");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Question", b =>
-                {
-                    b.Navigation("AssignmentQuestions");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.Submission", b =>
-                {
-                    b.Navigation("SubmissionDetails");
-                });
-
-            modelBuilder.Entity("Entities.Contracts.User", b =>
-                {
-                    b.Navigation("CreatedAssignments");
-
-                    b.Navigation("CreatedQuestions");
-
-                    b.Navigation("EnrolledClassesLink");
-
-                    b.Navigation("GradedSubmissions");
-
-                    b.Navigation("SubmissionDetails");
-
-                    b.Navigation("SubmissionsAsStudent");
-
-                    b.Navigation("TaughtClassesLink");
-                });
-#pragma warning restore 612, 618
-        }
-    }
-}
diff --git a/TechHelper.Server/Migrations/20250610025810_assignment-not_required.cs b/TechHelper.Server/Migrations/20250610025810_assignment-not_required.cs
deleted file mode 100644
index 82726eb..0000000
--- a/TechHelper.Server/Migrations/20250610025810_assignment-not_required.cs
+++ /dev/null
@@ -1,93 +0,0 @@
-using System;
-using Microsoft.EntityFrameworkCore.Migrations;
-
-#nullable disable
-
-#pragma warning disable CA1814 // Prefer jagged arrays over multidimensional
-
-namespace TechHelper.Server.Migrations
-{
-    /// <inheritdoc />
-    public partial class assignmentnot_required : Migration
-    {
-        /// <inheritdoc />
-        protected override void Up(MigrationBuilder migrationBuilder)
-        {
-            migrationBuilder.DeleteData(
-                table: "AspNetRoles",
-                keyColumn: "Id",
-                keyValue: new Guid("02a808ba-bd16-4f90-bf2b-0bc42f767e00"));
-
-            migrationBuilder.DeleteData(
-                table: "AspNetRoles",
-                keyColumn: "Id",
-                keyValue: new Guid("9e526681-e57e-46b5-a01c-5731b27bfc4a"));
-
-            migrationBuilder.DeleteData(
-                table: "AspNetRoles",
-                keyColumn: "Id",
-                keyValue: new Guid("dfdfb884-4063-4161-84e0-9c225f4e883c"));
-
-            migrationBuilder.AlterColumn<Guid>(
-                name: "assignment",
-                table: "assignment_group",
-                type: "char(36)",
-                nullable: true,
-                collation: "ascii_general_ci",
-                oldClrType: typeof(Guid),
-                oldType: "char(36)")
-                .OldAnnotation("Relational:Collation", "ascii_general_ci");
-
-            migrationBuilder.InsertData(
-                table: "AspNetRoles",
-                columns: new[] { "Id", "ConcurrencyStamp", "Name", "NormalizedName" },
-                values: new object[,]
-                {
-                    { new Guid("b2e087e6-ea32-46c4-aeb3-09b936cd0cf4"), null, "Teacher", "TEACHER" },
-                    { new Guid("ba33e047-8354-4f2c-b8b1-1f46441c28fc"), null, "Administrator", "ADMINISTRATOR" },
-                    { new Guid("d4b41bc3-612e-49dd-aeda-6a98ea0e4e68"), null, "Student", "STUDENT" }
-                });
-        }
-
-        /// <inheritdoc />
-        protected override void Down(MigrationBuilder migrationBuilder)
-        {
-            migrationBuilder.DeleteData(
-                table: "AspNetRoles",
-                keyColumn: "Id",
-                keyValue: new Guid("b2e087e6-ea32-46c4-aeb3-09b936cd0cf4"));
-
-            migrationBuilder.DeleteData(
-                table: "AspNetRoles",
-                keyColumn: "Id",
-                keyValue: new Guid("ba33e047-8354-4f2c-b8b1-1f46441c28fc"));
-
-            migrationBuilder.DeleteData(
-                table: "AspNetRoles",
-                keyColumn: "Id",
-                keyValue: new Guid("d4b41bc3-612e-49dd-aeda-6a98ea0e4e68"));
-
-            migrationBuilder.AlterColumn<Guid>(
-                name: "assignment",
-                table: "assignment_group",
-                type: "char(36)",
-                nullable: false,
-                defaultValue: new Guid("00000000-0000-0000-0000-000000000000"),
-                collation: "ascii_general_ci",
-                oldClrType: typeof(Guid),
-                oldType: "char(36)",
-                oldNullable: true)
-                .OldAnnotation("Relational:Collation", "ascii_general_ci");
-
-            migrationBuilder.InsertData(
-                table: "AspNetRoles",
-                columns: new[] { "Id", "ConcurrencyStamp", "Name", "NormalizedName" },
-                values: new object[,]
-                {
-                    { new Guid("02a808ba-bd16-4f90-bf2b-0bc42f767e00"), null, "Administrator", "ADMINISTRATOR" },
-                    { new Guid("9e526681-e57e-46b5-a01c-5731b27bfc4a"), null, "Student", "STUDENT" },
-                    { new Guid("dfdfb884-4063-4161-84e0-9c225f4e883c"), null, "Teacher", "TEACHER" }
-                });
-        }
-    }
-}
diff --git a/TechHelper.Server/Migrations/20250610025325_init.Designer.cs b/TechHelper.Server/Migrations/20250619070929_init.Designer.cs
similarity index 79%
rename from TechHelper.Server/Migrations/20250610025325_init.Designer.cs
rename to TechHelper.Server/Migrations/20250619070929_init.Designer.cs
index aed4a18..6d3846f 100644
--- a/TechHelper.Server/Migrations/20250610025325_init.Designer.cs
+++ b/TechHelper.Server/Migrations/20250619070929_init.Designer.cs
@@ -12,7 +12,7 @@ using TechHelper.Context;
 namespace TechHelper.Server.Migrations
 {
     [DbContext(typeof(ApplicationContext))]
-    [Migration("20250610025325_init")]
+    [Migration("20250619070929_init")]
     partial class init
     {
         /// <inheritdoc />
@@ -36,7 +36,7 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("datetime(6)")
                         .HasColumnName("created_at");
 
-                    b.Property<Guid>("CreatedBy")
+                    b.Property<Guid>("CreatorId")
                         .HasColumnType("char(36)")
                         .HasColumnName("created_by");
 
@@ -53,9 +53,12 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("tinyint(1)")
                         .HasColumnName("deleted");
 
-                    b.Property<string>("SubjectArea")
-                        .IsRequired()
-                        .HasColumnType("longtext")
+                    b.Property<float>("Score")
+                        .HasColumnType("float")
+                        .HasColumnName("score");
+
+                    b.Property<byte>("SubjectArea")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("subject_area");
 
                     b.Property<string>("Title")
@@ -64,8 +67,8 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("varchar(255)")
                         .HasColumnName("title");
 
-                    b.Property<float?>("TotalPoints")
-                        .HasColumnType("float")
+                    b.Property<byte>("TotalQuestions")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("total_points");
 
                     b.Property<DateTime>("UpdatedAt")
@@ -77,7 +80,7 @@ namespace TechHelper.Server.Migrations
 
                     b.HasKey("Id");
 
-                    b.HasIndex("CreatedBy");
+                    b.HasIndex("CreatorId");
 
                     b.HasIndex("UserId");
 
@@ -151,61 +154,6 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("assignment_class", (string)null);
                 });
 
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<Guid?>("AssignmentId")
-                        .IsRequired()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("assignment");
-
-                    b.Property<string>("Descript")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("descript");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<byte>("Number")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("number");
-
-                    b.Property<Guid?>("ParentGroup")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("parent_group");
-
-                    b.Property<string>("Title")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("title");
-
-                    b.Property<float?>("TotalPoints")
-                        .HasColumnType("float")
-                        .HasColumnName("total_points");
-
-                    b.Property<bool>("ValidQuestionGroup")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("valid_question_group");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("AssignmentId");
-
-                    b.HasIndex("ParentGroup");
-
-                    b.ToTable("assignment_group", (string)null);
-                });
-
             modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
                 {
                     b.Property<Guid>("Id")
@@ -221,6 +169,10 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("datetime(6)")
                         .HasColumnName("created_at");
 
+                    b.Property<byte>("Index")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("question_number");
+
                     b.Property<bool>("IsDeleted")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("tinyint(1)")
@@ -231,10 +183,6 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("char(36)")
                         .HasColumnName("question_id");
 
-                    b.Property<byte>("QuestionNumber")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("question_number");
-
                     b.Property<float?>("Score")
                         .HasColumnType("float")
                         .HasColumnName("score");
@@ -248,6 +196,61 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("assignment_questions", (string)null);
                 });
 
+            modelBuilder.Entity("Entities.Contracts.AssignmentStruct", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)")
+                        .HasColumnName("id");
+
+                    b.Property<Guid?>("AssignmentId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("assignment");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasMaxLength(65535)
+                        .HasColumnType("longtext")
+                        .HasColumnName("descript");
+
+                    b.Property<byte>("Index")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("number");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("tinyint(1)")
+                        .HasDefaultValue(false)
+                        .HasColumnName("deleted");
+
+                    b.Property<byte>("Layout")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("layout");
+
+                    b.Property<Guid?>("ParentGroupId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("parent_group");
+
+                    b.Property<float?>("Score")
+                        .HasColumnType("float")
+                        .HasColumnName("total_points");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(65535)
+                        .HasColumnType("longtext")
+                        .HasColumnName("title");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("AssignmentId")
+                        .IsUnique();
+
+                    b.HasIndex("ParentGroupId");
+
+                    b.ToTable("assignment_group", (string)null);
+                });
+
             modelBuilder.Entity("Entities.Contracts.Class", b =>
                 {
                     b.Property<Guid>("Id")
@@ -337,9 +340,8 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("char(36)")
                         .HasColumnName("teacher_id");
 
-                    b.Property<string>("SubjectTaught")
-                        .IsRequired()
-                        .HasColumnType("longtext")
+                    b.Property<byte>("SubjectTaught")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("subject_taught");
 
                     b.HasKey("ClassId", "TeacherId");
@@ -349,6 +351,72 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("class_teachers", (string)null);
                 });
 
+            modelBuilder.Entity("Entities.Contracts.KeyPoint", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("varchar(255)");
+
+                    b.Property<Guid>("LessonID")
+                        .HasColumnType("char(36)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("LessonID");
+
+                    b.ToTable("key_point");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.Lesson", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasColumnType("longtext");
+
+                    b.Property<Guid>("TextbookID")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("varchar(255)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TextbookID");
+
+                    b.ToTable("lesson");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.LessonQuestion", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<Guid>("LessonID")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Question")
+                        .IsRequired()
+                        .HasColumnType("longtext");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("LessonID");
+
+                    b.ToTable("lesson_question");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Question", b =>
                 {
                     b.Property<Guid>("Id")
@@ -356,8 +424,7 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("char(36)")
                         .HasColumnName("id");
 
-                    b.Property<string>("CorrectAnswer")
-                        .IsRequired()
+                    b.Property<string>("Answer")
                         .HasMaxLength(65535)
                         .HasColumnType("longtext")
                         .HasColumnName("correct_answer");
@@ -369,53 +436,75 @@ namespace TechHelper.Server.Migrations
 
                     MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<DateTime>("CreatedAt"));
 
-                    b.Property<Guid>("CreatedBy")
+                    b.Property<Guid>("CreatorId")
                         .HasColumnType("char(36)")
                         .HasColumnName("created_by");
 
-                    b.Property<string>("DifficultyLevel")
-                        .IsRequired()
+                    b.Property<byte>("DifficultyLevel")
                         .HasMaxLength(10)
-                        .HasColumnType("varchar(10)")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("difficulty_level");
 
+                    b.Property<byte>("GroupState")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("group_state");
+
                     b.Property<bool>("IsDeleted")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("tinyint(1)")
                         .HasDefaultValue(false)
                         .HasColumnName("deleted");
 
-                    b.Property<string>("QuestionText")
+                    b.Property<Guid?>("KeyPointId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("key_point");
+
+                    b.Property<Guid?>("LessonId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("lesson");
+
+                    b.Property<string>("Options")
+                        .HasColumnType("longtext")
+                        .HasColumnName("options");
+
+                    b.Property<Guid?>("ParentQuestionId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("parent_question_group_id");
+
+                    b.Property<byte>("SubjectArea")
+                        .HasMaxLength(100)
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("subject_area");
+
+                    b.Property<string>("Title")
                         .IsRequired()
                         .HasMaxLength(65535)
                         .HasColumnType("longtext")
                         .HasColumnName("question_text");
 
-                    b.Property<string>("QuestionType")
-                        .IsRequired()
+                    b.Property<byte>("Type")
                         .HasMaxLength(20)
-                        .HasColumnType("varchar(20)")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("question_type");
 
-                    b.Property<string>("SubjectArea")
-                        .IsRequired()
-                        .HasMaxLength(100)
-                        .HasColumnType("varchar(100)")
-                        .HasColumnName("subject_area");
-
                     b.Property<DateTime>("UpdatedAt")
                         .IsConcurrencyToken()
                         .ValueGeneratedOnAddOrUpdate()
                         .HasColumnType("datetime(6)")
                         .HasColumnName("updated_at");
 
-                    b.Property<bool>("ValidQuestion")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("valid_question");
-
                     b.HasKey("Id");
 
-                    b.HasIndex("CreatedBy");
+                    b.HasIndex("CreatorId");
+
+                    b.HasIndex("KeyPointId");
+
+                    b.HasIndex("LessonId");
+
+                    b.HasIndex("ParentQuestionId");
+
+                    b.HasIndex("Title")
+                        .HasAnnotation("MySql:IndexPrefixLength", new[] { 20 });
 
                     b.ToTable("questions", (string)null);
                 });
@@ -439,7 +528,7 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("datetime(6)")
                         .HasColumnName("graded_at");
 
-                    b.Property<Guid?>("GradedBy")
+                    b.Property<Guid?>("GraderId")
                         .HasColumnType("char(36)")
                         .HasColumnName("graded_by");
 
@@ -459,10 +548,9 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("float")
                         .HasColumnName("overall_grade");
 
-                    b.Property<string>("Status")
-                        .IsRequired()
+                    b.Property<int>("Status")
                         .HasMaxLength(15)
-                        .HasColumnType("varchar(15)")
+                        .HasColumnType("int")
                         .HasColumnName("status");
 
                     b.Property<Guid>("StudentId")
@@ -477,7 +565,7 @@ namespace TechHelper.Server.Migrations
 
                     b.HasIndex("AssignmentId");
 
-                    b.HasIndex("GradedBy");
+                    b.HasIndex("GraderId");
 
                     b.HasIndex("StudentId");
 
@@ -552,6 +640,30 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("submission_details", (string)null);
                 });
 
+            modelBuilder.Entity("Entities.Contracts.Textbook", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<byte>("Grade")
+                        .HasColumnType("tinyint unsigned");
+
+                    b.Property<byte>("Publisher")
+                        .HasColumnType("tinyint unsigned");
+
+                    b.Property<byte>("SubjectArea")
+                        .HasColumnType("tinyint unsigned");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasColumnType("longtext");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("textbook");
+                });
+
             modelBuilder.Entity("Entities.Contracts.User", b =>
                 {
                     b.Property<Guid>("Id")
@@ -662,19 +774,19 @@ namespace TechHelper.Server.Migrations
                     b.HasData(
                         new
                         {
-                            Id = new Guid("9e526681-e57e-46b5-a01c-5731b27bfc4a"),
+                            Id = new Guid("895d8f32-714e-4a14-bd97-8fa262b83172"),
                             Name = "Student",
                             NormalizedName = "STUDENT"
                         },
                         new
                         {
-                            Id = new Guid("dfdfb884-4063-4161-84e0-9c225f4e883c"),
+                            Id = new Guid("d182c396-c656-42da-965a-d93c17a1f74f"),
                             Name = "Teacher",
                             NormalizedName = "TEACHER"
                         },
                         new
                         {
-                            Id = new Guid("02a808ba-bd16-4f90-bf2b-0bc42f767e00"),
+                            Id = new Guid("4e65fab9-3315-4474-b92c-bdab5a617e65"),
                             Name = "Administrator",
                             NormalizedName = "ADMINISTRATOR"
                         });
@@ -787,7 +899,7 @@ namespace TechHelper.Server.Migrations
                 {
                     b.HasOne("Entities.Contracts.User", "Creator")
                         .WithMany()
-                        .HasForeignKey("CreatedBy")
+                        .HasForeignKey("CreatorId")
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
@@ -828,27 +940,9 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("Class");
                 });
 
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
-                        .WithMany("AssignmentGroups")
-                        .HasForeignKey("AssignmentId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("Entities.Contracts.AssignmentGroup", "ParentAssignmentGroup")
-                        .WithMany("ChildAssignmentGroups")
-                        .HasForeignKey("ParentGroup")
-                        .OnDelete(DeleteBehavior.SetNull);
-
-                    b.Navigation("Assignment");
-
-                    b.Navigation("ParentAssignmentGroup");
-                });
-
             modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
                 {
-                    b.HasOne("Entities.Contracts.AssignmentGroup", "AssignmentGroup")
+                    b.HasOne("Entities.Contracts.AssignmentStruct", "AssignmentGroup")
                         .WithMany("AssignmentQuestions")
                         .HasForeignKey("AssignmentGroupId")
                         .OnDelete(DeleteBehavior.Cascade)
@@ -865,6 +959,22 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("Question");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.AssignmentStruct", b =>
+                {
+                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
+                        .WithOne("ExamStruct")
+                        .HasForeignKey("Entities.Contracts.AssignmentStruct", "AssignmentId");
+
+                    b.HasOne("Entities.Contracts.AssignmentStruct", "ParentGroup")
+                        .WithMany("ChildrenGroups")
+                        .HasForeignKey("ParentGroupId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("Assignment");
+
+                    b.Navigation("ParentGroup");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Class", b =>
                 {
                     b.HasOne("Entities.Contracts.User", "HeadTeacher")
@@ -914,15 +1024,69 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("Teacher");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.KeyPoint", b =>
+                {
+                    b.HasOne("Entities.Contracts.Lesson", "Lesson")
+                        .WithMany("KeyPoints")
+                        .HasForeignKey("LessonID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Lesson");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.Lesson", b =>
+                {
+                    b.HasOne("Entities.Contracts.Textbook", "Textbook")
+                        .WithMany("Lessons")
+                        .HasForeignKey("TextbookID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Textbook");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.LessonQuestion", b =>
+                {
+                    b.HasOne("Entities.Contracts.Lesson", "Lesson")
+                        .WithMany("LessonQuestions")
+                        .HasForeignKey("LessonID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Lesson");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Question", b =>
                 {
                     b.HasOne("Entities.Contracts.User", "Creator")
                         .WithMany("CreatedQuestions")
-                        .HasForeignKey("CreatedBy")
+                        .HasForeignKey("CreatorId")
                         .OnDelete(DeleteBehavior.Restrict)
                         .IsRequired();
 
+                    b.HasOne("Entities.Contracts.KeyPoint", "KeyPoint")
+                        .WithMany("Questions")
+                        .HasForeignKey("KeyPointId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("Entities.Contracts.Lesson", "Lesson")
+                        .WithMany("Questions")
+                        .HasForeignKey("LessonId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("Entities.Contracts.Question", "ParentQuestion")
+                        .WithMany("ChildrenQuestion")
+                        .HasForeignKey("ParentQuestionId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
                     b.Navigation("Creator");
+
+                    b.Navigation("KeyPoint");
+
+                    b.Navigation("Lesson");
+
+                    b.Navigation("ParentQuestion");
                 });
 
             modelBuilder.Entity("Entities.Contracts.Submission", b =>
@@ -935,7 +1099,7 @@ namespace TechHelper.Server.Migrations
 
                     b.HasOne("Entities.Contracts.User", "Grader")
                         .WithMany("GradedSubmissions")
-                        .HasForeignKey("GradedBy")
+                        .HasForeignKey("GraderId")
                         .OnDelete(DeleteBehavior.SetNull);
 
                     b.HasOne("Entities.Contracts.User", "Student")
@@ -959,7 +1123,7 @@ namespace TechHelper.Server.Migrations
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
-                    b.HasOne("Entities.Contracts.User", "User")
+                    b.HasOne("Entities.Contracts.User", "Student")
                         .WithMany("SubmissionDetails")
                         .HasForeignKey("StudentId")
                         .OnDelete(DeleteBehavior.Restrict)
@@ -973,9 +1137,9 @@ namespace TechHelper.Server.Migrations
 
                     b.Navigation("AssignmentQuestion");
 
-                    b.Navigation("Submission");
+                    b.Navigation("Student");
 
-                    b.Navigation("User");
+                    b.Navigation("Submission");
                 });
 
             modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRoleClaim<System.Guid>", b =>
@@ -1035,23 +1199,24 @@ namespace TechHelper.Server.Migrations
 
                     b.Navigation("AssignmentClasses");
 
-                    b.Navigation("AssignmentGroups");
+                    b.Navigation("ExamStruct")
+                        .IsRequired();
 
                     b.Navigation("Submissions");
                 });
 
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.Navigation("AssignmentQuestions");
-
-                    b.Navigation("ChildAssignmentGroups");
-                });
-
             modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
                 {
                     b.Navigation("SubmissionDetails");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.AssignmentStruct", b =>
+                {
+                    b.Navigation("AssignmentQuestions");
+
+                    b.Navigation("ChildrenGroups");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Class", b =>
                 {
                     b.Navigation("AssignmentClasses");
@@ -1061,9 +1226,25 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("ClassTeachers");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.KeyPoint", b =>
+                {
+                    b.Navigation("Questions");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.Lesson", b =>
+                {
+                    b.Navigation("KeyPoints");
+
+                    b.Navigation("LessonQuestions");
+
+                    b.Navigation("Questions");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Question", b =>
                 {
                     b.Navigation("AssignmentQuestions");
+
+                    b.Navigation("ChildrenQuestion");
                 });
 
             modelBuilder.Entity("Entities.Contracts.Submission", b =>
@@ -1071,6 +1252,11 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("SubmissionDetails");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.Textbook", b =>
+                {
+                    b.Navigation("Lessons");
+                });
+
             modelBuilder.Entity("Entities.Contracts.User", b =>
                 {
                     b.Navigation("CreatedAssignments");
diff --git a/TechHelper.Server/Migrations/20250610025325_init.cs b/TechHelper.Server/Migrations/20250619070929_init.cs
similarity index 81%
rename from TechHelper.Server/Migrations/20250610025325_init.cs
rename to TechHelper.Server/Migrations/20250619070929_init.cs
index 09a6d42..58557ad 100644
--- a/TechHelper.Server/Migrations/20250610025325_init.cs
+++ b/TechHelper.Server/Migrations/20250619070929_init.cs
@@ -77,6 +77,23 @@ namespace TechHelper.Server.Migrations
                 })
                 .Annotation("MySql:CharSet", "utf8mb4");
 
+            migrationBuilder.CreateTable(
+                name: "textbook",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
+                    Grade = table.Column<byte>(type: "tinyint unsigned", nullable: false),
+                    Title = table.Column<string>(type: "longtext", nullable: false)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    Publisher = table.Column<byte>(type: "tinyint unsigned", nullable: false),
+                    SubjectArea = table.Column<byte>(type: "tinyint unsigned", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_textbook", x => x.Id);
+                })
+                .Annotation("MySql:CharSet", "utf8mb4");
+
             migrationBuilder.CreateTable(
                 name: "AspNetRoleClaims",
                 columns: table => new
@@ -207,10 +224,10 @@ namespace TechHelper.Server.Migrations
                         .Annotation("MySql:CharSet", "utf8mb4"),
                     description = table.Column<string>(type: "longtext", nullable: false)
                         .Annotation("MySql:CharSet", "utf8mb4"),
-                    subject_area = table.Column<string>(type: "longtext", nullable: false)
-                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    subject_area = table.Column<byte>(type: "tinyint unsigned", nullable: false),
                     due_date = table.Column<DateTime>(type: "datetime(6)", nullable: false),
-                    total_points = table.Column<float>(type: "float", nullable: true),
+                    total_points = table.Column<byte>(type: "tinyint unsigned", nullable: false),
+                    score = table.Column<float>(type: "float", nullable: false),
                     created_by = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
                     created_at = table.Column<DateTime>(type: "datetime(6)", nullable: false),
                     updated_at = table.Column<DateTime>(type: "datetime(6)", nullable: false),
@@ -263,36 +280,25 @@ namespace TechHelper.Server.Migrations
                 .Annotation("MySql:CharSet", "utf8mb4");
 
             migrationBuilder.CreateTable(
-                name: "questions",
+                name: "lesson",
                 columns: table => new
                 {
-                    id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
-                    question_text = table.Column<string>(type: "longtext", maxLength: 65535, nullable: false)
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
+                    Title = table.Column<string>(type: "varchar(255)", maxLength: 255, nullable: false)
                         .Annotation("MySql:CharSet", "utf8mb4"),
-                    question_type = table.Column<string>(type: "varchar(20)", maxLength: 20, nullable: false)
+                    Description = table.Column<string>(type: "longtext", nullable: false)
                         .Annotation("MySql:CharSet", "utf8mb4"),
-                    correct_answer = table.Column<string>(type: "longtext", maxLength: 65535, nullable: false)
-                        .Annotation("MySql:CharSet", "utf8mb4"),
-                    difficulty_level = table.Column<string>(type: "varchar(10)", maxLength: 10, nullable: false)
-                        .Annotation("MySql:CharSet", "utf8mb4"),
-                    subject_area = table.Column<string>(type: "varchar(100)", maxLength: 100, nullable: false)
-                        .Annotation("MySql:CharSet", "utf8mb4"),
-                    created_by = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
-                    created_at = table.Column<DateTime>(type: "datetime(6)", nullable: false)
-                        .Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),
-                    updated_at = table.Column<DateTime>(type: "datetime(6)", rowVersion: true, nullable: false),
-                    deleted = table.Column<bool>(type: "tinyint(1)", nullable: false, defaultValue: false),
-                    valid_question = table.Column<bool>(type: "tinyint(1)", nullable: false)
+                    TextbookID = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci")
                 },
                 constraints: table =>
                 {
-                    table.PrimaryKey("PK_questions", x => x.id);
+                    table.PrimaryKey("PK_lesson", x => x.Id);
                     table.ForeignKey(
-                        name: "FK_questions_AspNetUsers_created_by",
-                        column: x => x.created_by,
-                        principalTable: "AspNetUsers",
+                        name: "FK_lesson_textbook_TextbookID",
+                        column: x => x.TextbookID,
+                        principalTable: "textbook",
                         principalColumn: "Id",
-                        onDelete: ReferentialAction.Restrict);
+                        onDelete: ReferentialAction.Cascade);
                 })
                 .Annotation("MySql:CharSet", "utf8mb4");
 
@@ -326,16 +332,16 @@ namespace TechHelper.Server.Migrations
                 columns: table => new
                 {
                     id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
-                    assignment = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
+                    assignment = table.Column<Guid>(type: "char(36)", nullable: true, collation: "ascii_general_ci"),
                     title = table.Column<string>(type: "longtext", maxLength: 65535, nullable: false)
                         .Annotation("MySql:CharSet", "utf8mb4"),
                     descript = table.Column<string>(type: "longtext", maxLength: 65535, nullable: false)
                         .Annotation("MySql:CharSet", "utf8mb4"),
+                    layout = table.Column<byte>(type: "tinyint unsigned", nullable: false),
                     total_points = table.Column<float>(type: "float", nullable: true),
                     number = table.Column<byte>(type: "tinyint unsigned", nullable: false),
                     parent_group = table.Column<Guid>(type: "char(36)", nullable: true, collation: "ascii_general_ci"),
-                    deleted = table.Column<bool>(type: "tinyint(1)", nullable: false, defaultValue: false),
-                    valid_question_group = table.Column<bool>(type: "tinyint(1)", nullable: false)
+                    deleted = table.Column<bool>(type: "tinyint(1)", nullable: false, defaultValue: false)
                 },
                 constraints: table =>
                 {
@@ -350,8 +356,7 @@ namespace TechHelper.Server.Migrations
                         name: "FK_assignment_group_assignments_assignment",
                         column: x => x.assignment,
                         principalTable: "assignments",
-                        principalColumn: "id",
-                        onDelete: ReferentialAction.Cascade);
+                        principalColumn: "id");
                 })
                 .Annotation("MySql:CharSet", "utf8mb4");
 
@@ -370,8 +375,7 @@ namespace TechHelper.Server.Migrations
                     graded_by = table.Column<Guid>(type: "char(36)", nullable: true, collation: "ascii_general_ci"),
                     graded_at = table.Column<DateTime>(type: "datetime(6)", nullable: true),
                     deleted = table.Column<bool>(type: "tinyint(1)", nullable: false, defaultValue: false),
-                    status = table.Column<string>(type: "varchar(15)", maxLength: 15, nullable: false)
-                        .Annotation("MySql:CharSet", "utf8mb4")
+                    status = table.Column<int>(type: "int", maxLength: 15, nullable: false)
                 },
                 constraints: table =>
                 {
@@ -457,8 +461,7 @@ namespace TechHelper.Server.Migrations
                 {
                     class_id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
                     teacher_id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
-                    subject_taught = table.Column<string>(type: "longtext", nullable: false)
-                        .Annotation("MySql:CharSet", "utf8mb4")
+                    subject_taught = table.Column<byte>(type: "tinyint unsigned", nullable: false)
                 },
                 constraints: table =>
                 {
@@ -478,6 +481,102 @@ namespace TechHelper.Server.Migrations
                 })
                 .Annotation("MySql:CharSet", "utf8mb4");
 
+            migrationBuilder.CreateTable(
+                name: "key_point",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
+                    Key = table.Column<string>(type: "varchar(255)", maxLength: 255, nullable: false)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    LessonID = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_key_point", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_key_point_lesson_LessonID",
+                        column: x => x.LessonID,
+                        principalTable: "lesson",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                })
+                .Annotation("MySql:CharSet", "utf8mb4");
+
+            migrationBuilder.CreateTable(
+                name: "lesson_question",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
+                    Question = table.Column<string>(type: "longtext", nullable: false)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    LessonID = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_lesson_question", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_lesson_question_lesson_LessonID",
+                        column: x => x.LessonID,
+                        principalTable: "lesson",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                })
+                .Annotation("MySql:CharSet", "utf8mb4");
+
+            migrationBuilder.CreateTable(
+                name: "questions",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
+                    question_text = table.Column<string>(type: "longtext", maxLength: 65535, nullable: false)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    correct_answer = table.Column<string>(type: "longtext", maxLength: 65535, nullable: true)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    question_type = table.Column<byte>(type: "tinyint unsigned", maxLength: 20, nullable: false),
+                    difficulty_level = table.Column<byte>(type: "tinyint unsigned", maxLength: 10, nullable: false),
+                    subject_area = table.Column<byte>(type: "tinyint unsigned", maxLength: 100, nullable: false),
+                    group_state = table.Column<byte>(type: "tinyint unsigned", nullable: false),
+                    options = table.Column<string>(type: "longtext", nullable: true)
+                        .Annotation("MySql:CharSet", "utf8mb4"),
+                    key_point = table.Column<Guid>(type: "char(36)", nullable: true, collation: "ascii_general_ci"),
+                    lesson = table.Column<Guid>(type: "char(36)", nullable: true, collation: "ascii_general_ci"),
+                    parent_question_group_id = table.Column<Guid>(type: "char(36)", nullable: true, collation: "ascii_general_ci"),
+                    created_by = table.Column<Guid>(type: "char(36)", nullable: false, collation: "ascii_general_ci"),
+                    created_at = table.Column<DateTime>(type: "datetime(6)", nullable: false)
+                        .Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),
+                    updated_at = table.Column<DateTime>(type: "datetime(6)", rowVersion: true, nullable: false),
+                    deleted = table.Column<bool>(type: "tinyint(1)", nullable: false, defaultValue: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_questions", x => x.id);
+                    table.ForeignKey(
+                        name: "FK_questions_AspNetUsers_created_by",
+                        column: x => x.created_by,
+                        principalTable: "AspNetUsers",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_questions_key_point_key_point",
+                        column: x => x.key_point,
+                        principalTable: "key_point",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_questions_lesson_lesson",
+                        column: x => x.lesson,
+                        principalTable: "lesson",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "FK_questions_questions_parent_question_group_id",
+                        column: x => x.parent_question_group_id,
+                        principalTable: "questions",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.SetNull);
+                })
+                .Annotation("MySql:CharSet", "utf8mb4");
+
             migrationBuilder.CreateTable(
                 name: "assignment_questions",
                 columns: table => new
@@ -556,9 +655,9 @@ namespace TechHelper.Server.Migrations
                 columns: new[] { "Id", "ConcurrencyStamp", "Name", "NormalizedName" },
                 values: new object[,]
                 {
-                    { new Guid("02a808ba-bd16-4f90-bf2b-0bc42f767e00"), null, "Administrator", "ADMINISTRATOR" },
-                    { new Guid("9e526681-e57e-46b5-a01c-5731b27bfc4a"), null, "Student", "STUDENT" },
-                    { new Guid("dfdfb884-4063-4161-84e0-9c225f4e883c"), null, "Teacher", "TEACHER" }
+                    { new Guid("4e65fab9-3315-4474-b92c-bdab5a617e65"), null, "Administrator", "ADMINISTRATOR" },
+                    { new Guid("895d8f32-714e-4a14-bd97-8fa262b83172"), null, "Student", "STUDENT" },
+                    { new Guid("d182c396-c656-42da-965a-d93c17a1f74f"), null, "Teacher", "TEACHER" }
                 });
 
             migrationBuilder.CreateIndex(
@@ -611,7 +710,8 @@ namespace TechHelper.Server.Migrations
             migrationBuilder.CreateIndex(
                 name: "IX_assignment_group_assignment",
                 table: "assignment_group",
-                column: "assignment");
+                column: "assignment",
+                unique: true);
 
             migrationBuilder.CreateIndex(
                 name: "IX_assignment_group_parent_group",
@@ -653,11 +753,47 @@ namespace TechHelper.Server.Migrations
                 table: "classes",
                 column: "head_teacher_id");
 
+            migrationBuilder.CreateIndex(
+                name: "IX_key_point_LessonID",
+                table: "key_point",
+                column: "LessonID");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_lesson_TextbookID",
+                table: "lesson",
+                column: "TextbookID");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_lesson_question_LessonID",
+                table: "lesson_question",
+                column: "LessonID");
+
             migrationBuilder.CreateIndex(
                 name: "IX_questions_created_by",
                 table: "questions",
                 column: "created_by");
 
+            migrationBuilder.CreateIndex(
+                name: "IX_questions_key_point",
+                table: "questions",
+                column: "key_point");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_questions_lesson",
+                table: "questions",
+                column: "lesson");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_questions_parent_question_group_id",
+                table: "questions",
+                column: "parent_question_group_id");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_questions_question_text",
+                table: "questions",
+                column: "question_text")
+                .Annotation("MySql:IndexPrefixLength", new[] { 20 });
+
             migrationBuilder.CreateIndex(
                 name: "IX_submission_details_assignment_question_id",
                 table: "submission_details",
@@ -719,6 +855,9 @@ namespace TechHelper.Server.Migrations
             migrationBuilder.DropTable(
                 name: "class_teachers");
 
+            migrationBuilder.DropTable(
+                name: "lesson_question");
+
             migrationBuilder.DropTable(
                 name: "submission_details");
 
@@ -743,8 +882,17 @@ namespace TechHelper.Server.Migrations
             migrationBuilder.DropTable(
                 name: "assignments");
 
+            migrationBuilder.DropTable(
+                name: "key_point");
+
             migrationBuilder.DropTable(
                 name: "AspNetUsers");
+
+            migrationBuilder.DropTable(
+                name: "lesson");
+
+            migrationBuilder.DropTable(
+                name: "textbook");
         }
     }
 }
diff --git a/TechHelper.Server/Migrations/ApplicationContextModelSnapshot.cs b/TechHelper.Server/Migrations/ApplicationContextModelSnapshot.cs
index 260e7ce..b7a137f 100644
--- a/TechHelper.Server/Migrations/ApplicationContextModelSnapshot.cs
+++ b/TechHelper.Server/Migrations/ApplicationContextModelSnapshot.cs
@@ -33,7 +33,7 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("datetime(6)")
                         .HasColumnName("created_at");
 
-                    b.Property<Guid>("CreatedBy")
+                    b.Property<Guid>("CreatorId")
                         .HasColumnType("char(36)")
                         .HasColumnName("created_by");
 
@@ -50,9 +50,12 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("tinyint(1)")
                         .HasColumnName("deleted");
 
-                    b.Property<string>("SubjectArea")
-                        .IsRequired()
-                        .HasColumnType("longtext")
+                    b.Property<float>("Score")
+                        .HasColumnType("float")
+                        .HasColumnName("score");
+
+                    b.Property<byte>("SubjectArea")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("subject_area");
 
                     b.Property<string>("Title")
@@ -61,8 +64,8 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("varchar(255)")
                         .HasColumnName("title");
 
-                    b.Property<float?>("TotalPoints")
-                        .HasColumnType("float")
+                    b.Property<byte>("TotalQuestions")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("total_points");
 
                     b.Property<DateTime>("UpdatedAt")
@@ -74,7 +77,7 @@ namespace TechHelper.Server.Migrations
 
                     b.HasKey("Id");
 
-                    b.HasIndex("CreatedBy");
+                    b.HasIndex("CreatorId");
 
                     b.HasIndex("UserId");
 
@@ -148,60 +151,6 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("assignment_class", (string)null);
                 });
 
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("char(36)")
-                        .HasColumnName("id");
-
-                    b.Property<Guid?>("AssignmentId")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("assignment");
-
-                    b.Property<string>("Descript")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("descript");
-
-                    b.Property<bool>("IsDeleted")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("tinyint(1)")
-                        .HasDefaultValue(false)
-                        .HasColumnName("deleted");
-
-                    b.Property<byte>("Number")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("number");
-
-                    b.Property<Guid?>("ParentGroup")
-                        .HasColumnType("char(36)")
-                        .HasColumnName("parent_group");
-
-                    b.Property<string>("Title")
-                        .IsRequired()
-                        .HasMaxLength(65535)
-                        .HasColumnType("longtext")
-                        .HasColumnName("title");
-
-                    b.Property<float?>("TotalPoints")
-                        .HasColumnType("float")
-                        .HasColumnName("total_points");
-
-                    b.Property<bool>("ValidQuestionGroup")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("valid_question_group");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("AssignmentId");
-
-                    b.HasIndex("ParentGroup");
-
-                    b.ToTable("assignment_group", (string)null);
-                });
-
             modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
                 {
                     b.Property<Guid>("Id")
@@ -217,6 +166,10 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("datetime(6)")
                         .HasColumnName("created_at");
 
+                    b.Property<byte>("Index")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("question_number");
+
                     b.Property<bool>("IsDeleted")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("tinyint(1)")
@@ -227,10 +180,6 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("char(36)")
                         .HasColumnName("question_id");
 
-                    b.Property<byte>("QuestionNumber")
-                        .HasColumnType("tinyint unsigned")
-                        .HasColumnName("question_number");
-
                     b.Property<float?>("Score")
                         .HasColumnType("float")
                         .HasColumnName("score");
@@ -244,6 +193,61 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("assignment_questions", (string)null);
                 });
 
+            modelBuilder.Entity("Entities.Contracts.AssignmentStruct", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)")
+                        .HasColumnName("id");
+
+                    b.Property<Guid?>("AssignmentId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("assignment");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasMaxLength(65535)
+                        .HasColumnType("longtext")
+                        .HasColumnName("descript");
+
+                    b.Property<byte>("Index")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("number");
+
+                    b.Property<bool>("IsDeleted")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("tinyint(1)")
+                        .HasDefaultValue(false)
+                        .HasColumnName("deleted");
+
+                    b.Property<byte>("Layout")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("layout");
+
+                    b.Property<Guid?>("ParentGroupId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("parent_group");
+
+                    b.Property<float?>("Score")
+                        .HasColumnType("float")
+                        .HasColumnName("total_points");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(65535)
+                        .HasColumnType("longtext")
+                        .HasColumnName("title");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("AssignmentId")
+                        .IsUnique();
+
+                    b.HasIndex("ParentGroupId");
+
+                    b.ToTable("assignment_group", (string)null);
+                });
+
             modelBuilder.Entity("Entities.Contracts.Class", b =>
                 {
                     b.Property<Guid>("Id")
@@ -333,9 +337,8 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("char(36)")
                         .HasColumnName("teacher_id");
 
-                    b.Property<string>("SubjectTaught")
-                        .IsRequired()
-                        .HasColumnType("longtext")
+                    b.Property<byte>("SubjectTaught")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("subject_taught");
 
                     b.HasKey("ClassId", "TeacherId");
@@ -345,6 +348,72 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("class_teachers", (string)null);
                 });
 
+            modelBuilder.Entity("Entities.Contracts.KeyPoint", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("varchar(255)");
+
+                    b.Property<Guid>("LessonID")
+                        .HasColumnType("char(36)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("LessonID");
+
+                    b.ToTable("key_point");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.Lesson", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasColumnType("longtext");
+
+                    b.Property<Guid>("TextbookID")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("varchar(255)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TextbookID");
+
+                    b.ToTable("lesson");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.LessonQuestion", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<Guid>("LessonID")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Question")
+                        .IsRequired()
+                        .HasColumnType("longtext");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("LessonID");
+
+                    b.ToTable("lesson_question");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Question", b =>
                 {
                     b.Property<Guid>("Id")
@@ -352,8 +421,7 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("char(36)")
                         .HasColumnName("id");
 
-                    b.Property<string>("CorrectAnswer")
-                        .IsRequired()
+                    b.Property<string>("Answer")
                         .HasMaxLength(65535)
                         .HasColumnType("longtext")
                         .HasColumnName("correct_answer");
@@ -365,53 +433,75 @@ namespace TechHelper.Server.Migrations
 
                     MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<DateTime>("CreatedAt"));
 
-                    b.Property<Guid>("CreatedBy")
+                    b.Property<Guid>("CreatorId")
                         .HasColumnType("char(36)")
                         .HasColumnName("created_by");
 
-                    b.Property<string>("DifficultyLevel")
-                        .IsRequired()
+                    b.Property<byte>("DifficultyLevel")
                         .HasMaxLength(10)
-                        .HasColumnType("varchar(10)")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("difficulty_level");
 
+                    b.Property<byte>("GroupState")
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("group_state");
+
                     b.Property<bool>("IsDeleted")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("tinyint(1)")
                         .HasDefaultValue(false)
                         .HasColumnName("deleted");
 
-                    b.Property<string>("QuestionText")
+                    b.Property<Guid?>("KeyPointId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("key_point");
+
+                    b.Property<Guid?>("LessonId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("lesson");
+
+                    b.Property<string>("Options")
+                        .HasColumnType("longtext")
+                        .HasColumnName("options");
+
+                    b.Property<Guid?>("ParentQuestionId")
+                        .HasColumnType("char(36)")
+                        .HasColumnName("parent_question_group_id");
+
+                    b.Property<byte>("SubjectArea")
+                        .HasMaxLength(100)
+                        .HasColumnType("tinyint unsigned")
+                        .HasColumnName("subject_area");
+
+                    b.Property<string>("Title")
                         .IsRequired()
                         .HasMaxLength(65535)
                         .HasColumnType("longtext")
                         .HasColumnName("question_text");
 
-                    b.Property<string>("QuestionType")
-                        .IsRequired()
+                    b.Property<byte>("Type")
                         .HasMaxLength(20)
-                        .HasColumnType("varchar(20)")
+                        .HasColumnType("tinyint unsigned")
                         .HasColumnName("question_type");
 
-                    b.Property<string>("SubjectArea")
-                        .IsRequired()
-                        .HasMaxLength(100)
-                        .HasColumnType("varchar(100)")
-                        .HasColumnName("subject_area");
-
                     b.Property<DateTime>("UpdatedAt")
                         .IsConcurrencyToken()
                         .ValueGeneratedOnAddOrUpdate()
                         .HasColumnType("datetime(6)")
                         .HasColumnName("updated_at");
 
-                    b.Property<bool>("ValidQuestion")
-                        .HasColumnType("tinyint(1)")
-                        .HasColumnName("valid_question");
-
                     b.HasKey("Id");
 
-                    b.HasIndex("CreatedBy");
+                    b.HasIndex("CreatorId");
+
+                    b.HasIndex("KeyPointId");
+
+                    b.HasIndex("LessonId");
+
+                    b.HasIndex("ParentQuestionId");
+
+                    b.HasIndex("Title")
+                        .HasAnnotation("MySql:IndexPrefixLength", new[] { 20 });
 
                     b.ToTable("questions", (string)null);
                 });
@@ -435,7 +525,7 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("datetime(6)")
                         .HasColumnName("graded_at");
 
-                    b.Property<Guid?>("GradedBy")
+                    b.Property<Guid?>("GraderId")
                         .HasColumnType("char(36)")
                         .HasColumnName("graded_by");
 
@@ -455,10 +545,9 @@ namespace TechHelper.Server.Migrations
                         .HasColumnType("float")
                         .HasColumnName("overall_grade");
 
-                    b.Property<string>("Status")
-                        .IsRequired()
+                    b.Property<int>("Status")
                         .HasMaxLength(15)
-                        .HasColumnType("varchar(15)")
+                        .HasColumnType("int")
                         .HasColumnName("status");
 
                     b.Property<Guid>("StudentId")
@@ -473,7 +562,7 @@ namespace TechHelper.Server.Migrations
 
                     b.HasIndex("AssignmentId");
 
-                    b.HasIndex("GradedBy");
+                    b.HasIndex("GraderId");
 
                     b.HasIndex("StudentId");
 
@@ -548,6 +637,30 @@ namespace TechHelper.Server.Migrations
                     b.ToTable("submission_details", (string)null);
                 });
 
+            modelBuilder.Entity("Entities.Contracts.Textbook", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<byte>("Grade")
+                        .HasColumnType("tinyint unsigned");
+
+                    b.Property<byte>("Publisher")
+                        .HasColumnType("tinyint unsigned");
+
+                    b.Property<byte>("SubjectArea")
+                        .HasColumnType("tinyint unsigned");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasColumnType("longtext");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("textbook");
+                });
+
             modelBuilder.Entity("Entities.Contracts.User", b =>
                 {
                     b.Property<Guid>("Id")
@@ -658,19 +771,19 @@ namespace TechHelper.Server.Migrations
                     b.HasData(
                         new
                         {
-                            Id = new Guid("d4b41bc3-612e-49dd-aeda-6a98ea0e4e68"),
+                            Id = new Guid("895d8f32-714e-4a14-bd97-8fa262b83172"),
                             Name = "Student",
                             NormalizedName = "STUDENT"
                         },
                         new
                         {
-                            Id = new Guid("b2e087e6-ea32-46c4-aeb3-09b936cd0cf4"),
+                            Id = new Guid("d182c396-c656-42da-965a-d93c17a1f74f"),
                             Name = "Teacher",
                             NormalizedName = "TEACHER"
                         },
                         new
                         {
-                            Id = new Guid("ba33e047-8354-4f2c-b8b1-1f46441c28fc"),
+                            Id = new Guid("4e65fab9-3315-4474-b92c-bdab5a617e65"),
                             Name = "Administrator",
                             NormalizedName = "ADMINISTRATOR"
                         });
@@ -783,7 +896,7 @@ namespace TechHelper.Server.Migrations
                 {
                     b.HasOne("Entities.Contracts.User", "Creator")
                         .WithMany()
-                        .HasForeignKey("CreatedBy")
+                        .HasForeignKey("CreatorId")
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
@@ -824,26 +937,9 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("Class");
                 });
 
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
-                        .WithMany("AssignmentGroups")
-                        .HasForeignKey("AssignmentId")
-                        .OnDelete(DeleteBehavior.Cascade);
-
-                    b.HasOne("Entities.Contracts.AssignmentGroup", "ParentAssignmentGroup")
-                        .WithMany("ChildAssignmentGroups")
-                        .HasForeignKey("ParentGroup")
-                        .OnDelete(DeleteBehavior.SetNull);
-
-                    b.Navigation("Assignment");
-
-                    b.Navigation("ParentAssignmentGroup");
-                });
-
             modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
                 {
-                    b.HasOne("Entities.Contracts.AssignmentGroup", "AssignmentGroup")
+                    b.HasOne("Entities.Contracts.AssignmentStruct", "AssignmentGroup")
                         .WithMany("AssignmentQuestions")
                         .HasForeignKey("AssignmentGroupId")
                         .OnDelete(DeleteBehavior.Cascade)
@@ -860,6 +956,22 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("Question");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.AssignmentStruct", b =>
+                {
+                    b.HasOne("Entities.Contracts.Assignment", "Assignment")
+                        .WithOne("ExamStruct")
+                        .HasForeignKey("Entities.Contracts.AssignmentStruct", "AssignmentId");
+
+                    b.HasOne("Entities.Contracts.AssignmentStruct", "ParentGroup")
+                        .WithMany("ChildrenGroups")
+                        .HasForeignKey("ParentGroupId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("Assignment");
+
+                    b.Navigation("ParentGroup");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Class", b =>
                 {
                     b.HasOne("Entities.Contracts.User", "HeadTeacher")
@@ -909,15 +1021,69 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("Teacher");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.KeyPoint", b =>
+                {
+                    b.HasOne("Entities.Contracts.Lesson", "Lesson")
+                        .WithMany("KeyPoints")
+                        .HasForeignKey("LessonID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Lesson");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.Lesson", b =>
+                {
+                    b.HasOne("Entities.Contracts.Textbook", "Textbook")
+                        .WithMany("Lessons")
+                        .HasForeignKey("TextbookID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Textbook");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.LessonQuestion", b =>
+                {
+                    b.HasOne("Entities.Contracts.Lesson", "Lesson")
+                        .WithMany("LessonQuestions")
+                        .HasForeignKey("LessonID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Lesson");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Question", b =>
                 {
                     b.HasOne("Entities.Contracts.User", "Creator")
                         .WithMany("CreatedQuestions")
-                        .HasForeignKey("CreatedBy")
+                        .HasForeignKey("CreatorId")
                         .OnDelete(DeleteBehavior.Restrict)
                         .IsRequired();
 
+                    b.HasOne("Entities.Contracts.KeyPoint", "KeyPoint")
+                        .WithMany("Questions")
+                        .HasForeignKey("KeyPointId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("Entities.Contracts.Lesson", "Lesson")
+                        .WithMany("Questions")
+                        .HasForeignKey("LessonId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.HasOne("Entities.Contracts.Question", "ParentQuestion")
+                        .WithMany("ChildrenQuestion")
+                        .HasForeignKey("ParentQuestionId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
                     b.Navigation("Creator");
+
+                    b.Navigation("KeyPoint");
+
+                    b.Navigation("Lesson");
+
+                    b.Navigation("ParentQuestion");
                 });
 
             modelBuilder.Entity("Entities.Contracts.Submission", b =>
@@ -930,7 +1096,7 @@ namespace TechHelper.Server.Migrations
 
                     b.HasOne("Entities.Contracts.User", "Grader")
                         .WithMany("GradedSubmissions")
-                        .HasForeignKey("GradedBy")
+                        .HasForeignKey("GraderId")
                         .OnDelete(DeleteBehavior.SetNull);
 
                     b.HasOne("Entities.Contracts.User", "Student")
@@ -954,7 +1120,7 @@ namespace TechHelper.Server.Migrations
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
-                    b.HasOne("Entities.Contracts.User", "User")
+                    b.HasOne("Entities.Contracts.User", "Student")
                         .WithMany("SubmissionDetails")
                         .HasForeignKey("StudentId")
                         .OnDelete(DeleteBehavior.Restrict)
@@ -968,9 +1134,9 @@ namespace TechHelper.Server.Migrations
 
                     b.Navigation("AssignmentQuestion");
 
-                    b.Navigation("Submission");
+                    b.Navigation("Student");
 
-                    b.Navigation("User");
+                    b.Navigation("Submission");
                 });
 
             modelBuilder.Entity("Microsoft.AspNetCore.Identity.IdentityRoleClaim<System.Guid>", b =>
@@ -1030,23 +1196,24 @@ namespace TechHelper.Server.Migrations
 
                     b.Navigation("AssignmentClasses");
 
-                    b.Navigation("AssignmentGroups");
+                    b.Navigation("ExamStruct")
+                        .IsRequired();
 
                     b.Navigation("Submissions");
                 });
 
-            modelBuilder.Entity("Entities.Contracts.AssignmentGroup", b =>
-                {
-                    b.Navigation("AssignmentQuestions");
-
-                    b.Navigation("ChildAssignmentGroups");
-                });
-
             modelBuilder.Entity("Entities.Contracts.AssignmentQuestion", b =>
                 {
                     b.Navigation("SubmissionDetails");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.AssignmentStruct", b =>
+                {
+                    b.Navigation("AssignmentQuestions");
+
+                    b.Navigation("ChildrenGroups");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Class", b =>
                 {
                     b.Navigation("AssignmentClasses");
@@ -1056,9 +1223,25 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("ClassTeachers");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.KeyPoint", b =>
+                {
+                    b.Navigation("Questions");
+                });
+
+            modelBuilder.Entity("Entities.Contracts.Lesson", b =>
+                {
+                    b.Navigation("KeyPoints");
+
+                    b.Navigation("LessonQuestions");
+
+                    b.Navigation("Questions");
+                });
+
             modelBuilder.Entity("Entities.Contracts.Question", b =>
                 {
                     b.Navigation("AssignmentQuestions");
+
+                    b.Navigation("ChildrenQuestion");
                 });
 
             modelBuilder.Entity("Entities.Contracts.Submission", b =>
@@ -1066,6 +1249,11 @@ namespace TechHelper.Server.Migrations
                     b.Navigation("SubmissionDetails");
                 });
 
+            modelBuilder.Entity("Entities.Contracts.Textbook", b =>
+                {
+                    b.Navigation("Lessons");
+                });
+
             modelBuilder.Entity("Entities.Contracts.User", b =>
                 {
                     b.Navigation("CreatedAssignments");
diff --git a/TechHelper.Server/Program.cs b/TechHelper.Server/Program.cs
index 2588e43..9a6b3fa 100644
--- a/TechHelper.Server/Program.cs
+++ b/TechHelper.Server/Program.cs
@@ -11,6 +11,7 @@ using System.Text;
 using TechHelper.Features;
 using TechHelper.Services;
 using TechHelper.Server.Services;
+using TechHelper.Server.Repositories;
 
 
 var builder = WebApplication.CreateBuilder(args);
@@ -26,7 +27,7 @@ builder.Services.AddDbContext<ApplicationContext>(options =>
 ).AddUnitOfWork<ApplicationContext>()
 .AddCustomRepository<Assignment, AssignmentRepository>()
 .AddCustomRepository<AssignmentAttachment, AssignmentAttachmentRepository>()
-.AddCustomRepository<AssignmentGroup, AssignmentGroupRepository>()
+.AddCustomRepository<AssignmentStruct, AssignmentGroupRepository>()
 .AddCustomRepository<AssignmentQuestion, AssignmentQuestionRepository>()
 .AddCustomRepository<Class, ClassRepository>()
 .AddCustomRepository<ClassStudent, ClassStudentRepository>()
@@ -85,6 +86,7 @@ builder.Services.AddScoped<IEmailSender, QEmailSender>();
 builder.Services.AddTransient<IUserRegistrationService, UserRegistrationService>();
 builder.Services.AddScoped<IClassService, ClassService>();
 builder.Services.AddScoped<IExamService, ExamService>();
+builder.Services.AddScoped<IExamRepository, ExamRepository>();	
 
 
 builder.Services.AddEndpointsApiExplorer();
diff --git a/TechHelper.Server/Repositories/ExamRepository.cs b/TechHelper.Server/Repositories/ExamRepository.cs
new file mode 100644
index 0000000..e27d321
--- /dev/null
+++ b/TechHelper.Server/Repositories/ExamRepository.cs
@@ -0,0 +1,92 @@
+using Entities.Contracts;
+using Entities.DTO;
+using Microsoft.EntityFrameworkCore;
+using SharedDATA.Api;
+using TechHelper.Repository;
+
+namespace TechHelper.Server.Repositories
+{
+	public class ExamRepository : IExamRepository
+	{
+		private readonly IUnitOfWork _unitOfWork;
+		private readonly IRepository<Assignment> _assignmentRepo;
+		private readonly IRepository<AssignmentStruct> _assignmentGroupRepo;
+		private readonly IRepository<Question> _questionRepo;
+
+		public ExamRepository(IUnitOfWork unitOfWork)
+		{
+			_unitOfWork = unitOfWork;
+			_assignmentRepo = _unitOfWork.GetRepository<Assignment>();
+			_assignmentGroupRepo = _unitOfWork.GetRepository<AssignmentStruct>();
+		}
+
+		public async Task<Assignment?> GetFullExamByIdAsync(Guid assignmentId)
+		{
+
+			return null;
+		}
+
+
+		private async Task LoadSubGroupsRecursive(AssignmentStruct group)
+		{
+			// EF Core 已经加载了下一层，我们需要确保更深层次的加载
+			var groupWithChildren = await _assignmentGroupRepo.GetFirstOrDefaultAsync(
+				predicate: g => g.Id == group.Id,
+				include: source => source
+					.Include(g => g.ChildrenGroups.Where(cg => !cg.IsDeleted))
+						.ThenInclude(cg => cg.AssignmentQuestions.Where(aq => !aq.IsDeleted))
+						.ThenInclude(aq => aq.Question)
+					.Include(g => g.AssignmentQuestions.Where(aq => !aq.IsDeleted))
+						.ThenInclude(aq => aq.Question)
+			);
+
+			group.ChildrenGroups = groupWithChildren.ChildrenGroups;
+			group.AssignmentQuestions = groupWithChildren.AssignmentQuestions;
+
+			if (group.ChildrenGroups != null)
+			{
+				foreach (var child in group.ChildrenGroups)
+				{
+					await LoadSubGroupsRecursive(child);
+				}
+			}
+		}
+
+		public async Task<IEnumerable<Assignment>> GetExamPreviewsByUserAsync(Guid userId)
+		{
+			return await _assignmentRepo.GetAllAsync(
+				predicate: a => a.CreatorId == userId && !a.IsDeleted);
+		}
+
+		public async Task AddAsync(Assignment assignment)
+		{
+			await _assignmentRepo.InsertAsync(assignment);
+		}
+
+
+		public async Task AddAsync(QuestionGroupDto qg)
+		{
+			if (qg.ValidQuestionGroup)
+			{
+
+			}
+		}
+
+		public async Task AddAsync(AssignmentStruct assignment)
+		{
+
+		}
+
+		public async Task AddAsync(AssignmentQuestion assignment)
+		{
+		}
+
+		public async Task AddAsync(Question assignment)
+		{
+		}
+
+		public async Task AddAsync(AssignmentClass assignment)
+		{
+		}
+	}
+}
diff --git a/TechHelper.Server/Repository/IExamRepository.cs b/TechHelper.Server/Repositories/IExamRepository.cs
similarity index 79%
rename from TechHelper.Server/Repository/IExamRepository.cs
rename to TechHelper.Server/Repositories/IExamRepository.cs
index 2b5642e..2006d92 100644
--- a/TechHelper.Server/Repository/IExamRepository.cs
+++ b/TechHelper.Server/Repositories/IExamRepository.cs
@@ -1,6 +1,6 @@
 using Entities.Contracts;
 
-namespace TechHelper.Server.Repository
+namespace TechHelper.Server.Repositories
 {
 	public interface IExamRepository
 	{
@@ -23,5 +23,16 @@ namespace TechHelper.Server.Repository
 		/// </summary>
 		/// <param name="assignment">要添加的试卷实体。</param>
 		Task AddAsync(Assignment assignment);
+
+
+
+		Task AddAsync(AssignmentStruct assignment);
+
+		Task AddAsync(AssignmentQuestion assignment);
+
+		Task AddAsync(Question assignment);
+
+		Task AddAsync(AssignmentClass assignment);
+
 	}
 }
diff --git a/TechHelper.Server/Repository/AssignmentGroupRepository.cs b/TechHelper.Server/Repository/AssignmentGroupRepository.cs
index 00828a6..70785a0 100644
--- a/TechHelper.Server/Repository/AssignmentGroupRepository.cs
+++ b/TechHelper.Server/Repository/AssignmentGroupRepository.cs
@@ -5,7 +5,7 @@ using TechHelper.Context;
 
 namespace TechHelper.Repository
 {
-	public class AssignmentGroupRepository : Repository<AssignmentGroup>, IRepository<AssignmentGroup>
+	public class AssignmentGroupRepository : Repository<AssignmentStruct>, IRepository<AssignmentStruct>
 	{
 		public AssignmentGroupRepository(ApplicationContext dbContext) : base(dbContext)
 		{
diff --git a/TechHelper.Server/Repository/AssignmentRepository.cs b/TechHelper.Server/Repository/AssignmentRepository.cs
index 5b528b6..2648f4b 100644
--- a/TechHelper.Server/Repository/AssignmentRepository.cs
+++ b/TechHelper.Server/Repository/AssignmentRepository.cs
@@ -10,5 +10,10 @@ namespace TechHelper.Repository
 		public AssignmentRepository(ApplicationContext dbContext) : base(dbContext)
 		{
 		}
+
+		public void THISTEST()
+		{
+
+		}
 	}
 }
diff --git a/TechHelper.Server/Repository/ExamRepository.cs b/TechHelper.Server/Repository/ExamRepository.cs
deleted file mode 100644
index 191b525..0000000
--- a/TechHelper.Server/Repository/ExamRepository.cs
+++ /dev/null
@@ -1,96 +0,0 @@
-using Entities.Contracts;
-using Entities.DTO;
-using Microsoft.EntityFrameworkCore;
-using SharedDATA.Api;
-
-namespace TechHelper.Server.Repository
-{
-	public class ExamRepository : IExamRepository
-	{
-		private readonly IUnitOfWork _unitOfWork;
-		private readonly IRepository<Assignment> _assignmentRepo;
-		private readonly IRepository<AssignmentGroup> _assignmentGroupRepo;
-		private readonly IRepository<QuestionGroup> _questionGroupRepo;
-		private readonly IRepository<Question> _questionRepo;
-
-		public ExamRepository(IUnitOfWork unitOfWork)
-		{
-			_unitOfWork = unitOfWork;
-			_assignmentRepo = _unitOfWork.GetRepository<Assignment>();
-			_assignmentGroupRepo = _unitOfWork.GetRepository<AssignmentGroup>();
-		}
-
-		public async Task<Assignment?> GetFullExamByIdAsync(Guid assignmentId)
-		{
-
-			var assignment = await _assignmentRepo.GetFirstOrDefaultAsync(
-				predicate: a => a.Id == assignmentId && !a.IsDeleted,
-				include: source => source
-					.Include
-					(a => a.AssignmentGroups.Where(ag => ag.ParentGroup == null && !ag.IsDeleted)) // 加载根题组
-						.ThenInclude(ag => ag.ChildAssignmentGroups.Where(cag => !cag.IsDeleted)) // 加载子题组
-							.ThenInclude(cag => cag.AssignmentQuestions.Where(aq => !aq.IsDeleted)) // 加载子题组的题目
-								.ThenInclude(aq => aq.Question)
-					.Include(a => a.AssignmentGroups.Where(ag => ag.ParentGroup == null && !ag.IsDeleted)) // 再次从根开始，加载题组下的题目
-						.ThenInclude(ag => ag.AssignmentQuestions.Where(aq => !aq.IsDeleted))
-							.ThenInclude(aq => aq.Question)
-			);
-
-			if (assignment?.AssignmentGroups != null)
-			{
-				foreach (var rootGroup in assignment.AssignmentGroups)
-				{
-					await LoadSubGroupsRecursive(rootGroup);
-				}
-			}
-
-			return assignment;
-		}
-
-
-		private async Task LoadSubGroupsRecursive(AssignmentGroup group)
-		{
-			// EF Core 已经加载了下一层，我们需要确保更深层次的加载
-			var groupWithChildren = await _assignmentGroupRepo.GetFirstOrDefaultAsync(
-				predicate: g => g.Id == group.Id,
-				include: source => source
-					.Include(g => g.ChildAssignmentGroups.Where(cg => !cg.IsDeleted))
-						.ThenInclude(cg => cg.AssignmentQuestions.Where(aq => !aq.IsDeleted))
-						.ThenInclude(aq => aq.Question)
-					.Include(g => g.AssignmentQuestions.Where(aq => !aq.IsDeleted))
-						.ThenInclude(aq => aq.Question)
-			);
-
-			group.ChildAssignmentGroups = groupWithChildren.ChildAssignmentGroups;
-			group.AssignmentQuestions = groupWithChildren.AssignmentQuestions;
-
-			if (group.ChildAssignmentGroups != null)
-			{
-				foreach (var child in group.ChildAssignmentGroups)
-				{
-					await LoadSubGroupsRecursive(child);
-				}
-			}
-		}
-
-		public async Task<IEnumerable<Assignment>> GetExamPreviewsByUserAsync(Guid userId)
-		{
-			return await _assignmentRepo.GetAllAsync(
-				predicate: a => a.CreatedBy == userId && !a.IsDeleted);
-		}
-
-		public async Task AddAsync(Assignment assignment)
-		{
-			await _assignmentRepo.InsertAsync(assignment);
-		}
-
-
-		public async Task AddAsync(QuestionGroupDto qg)
-		{
-			if(qg.ValidQuestionGroup)
-			{
-
-			}
-		}
-	}
-}
diff --git a/TechHelper.Server/Repository/UserRepository.cs b/TechHelper.Server/Repository/UserRepository.cs
new file mode 100644
index 0000000..1f55c70
--- /dev/null
+++ b/TechHelper.Server/Repository/UserRepository.cs
@@ -0,0 +1,17 @@
+using Entities.Contracts;
+using Microsoft.EntityFrameworkCore;
+using SharedDATA.Api;
+using TechHelper.Context;
+
+namespace TechHelper.Repository
+{
+	public class UserRepository : Repository<User>, IRepository<User>
+	{
+		public UserRepository(ApplicationContext dbContext) : base(dbContext)
+		{
+			
+		}
+
+
+	}
+}
diff --git a/TechHelper.Server/Services/ApiResponse.cs b/TechHelper.Server/Services/ApiResponse.cs
deleted file mode 100644
index 6d46e39..0000000
--- a/TechHelper.Server/Services/ApiResponse.cs
+++ /dev/null
@@ -1,47 +0,0 @@
-namespace TechHelper.Services
-{
-	public class ApiResponse
-	{
-		public string Message { get; set; }
-		public bool Status { get; set; }
-		public object? Result { get; set; } 
-
-		private ApiResponse(bool status, string message, object? result)
-		{
-			Status = status;
-			Message = message;
-			Result = result;
-		}
-
-		public ApiResponse(string message, bool status = false)
-			: this(status, message, null) { }
-
-
-		public ApiResponse(bool status, object result)
-			: this(status, string.Empty, result) { } 
-
-
-
-		/// <summary>
-		/// 创建一个表示成功响应的 ApiResponse 实例。
-		/// </summary>
-		/// <param name="message">成功消息。</param>
-		/// <param name="result">可选的返回数据。</param>
-		/// <returns>ApiResponse 实例。</returns>
-		public static ApiResponse Success(string message = "操作成功。", object? result = null)
-		{
-			return new ApiResponse(true, message, result);
-		}
-
-		/// <summary>
-		/// 创建一个表示失败响应的 ApiResponse 实例。
-		/// </summary>
-		/// <param name="message">错误消息。</param>
-		/// <param name="result">可选的错误详情或数据。</param>
-		/// <returns>ApiResponse 实例。</returns>
-		public static ApiResponse Error(string message = "操作失败。", object? result = null)
-		{
-			return new ApiResponse(false, message, result);
-		}
-	}
-}
\ No newline at end of file
diff --git a/TechHelper.Server/Services/ClassService.cs b/TechHelper.Server/Services/ClassService.cs
index f22bf33..fed024e 100644
--- a/TechHelper.Server/Services/ClassService.cs
+++ b/TechHelper.Server/Services/ClassService.cs
@@ -197,7 +197,7 @@ namespace TechHelper.Services
 					{
 						ClassId = existingClass.Id,
 						TeacherId = existingClass.Id,
-						SubjectTaught = user.SubjectArea.ToString()
+						SubjectTaught = user.SubjectArea
 					};
 					await _work.GetRepository<ClassTeacher>().InsertAsync(classTeacher);
 
diff --git a/TechHelper.Server/Services/ExamService.cs b/TechHelper.Server/Services/ExamService.cs
index a7a2aa4..ca4365f 100644
--- a/TechHelper.Server/Services/ExamService.cs
+++ b/TechHelper.Server/Services/ExamService.cs
@@ -1,56 +1,149 @@
 using AutoMapper;
 using Entities.Contracts;
 using Entities.DTO;
-using Microsoft.AspNetCore.Identity;
-using Microsoft.EntityFrameworkCore;
-using MySqlConnector;
+using Microsoft.VisualBasic;
 using SharedDATA.Api;
+using TechHelper.Context;
+using TechHelper.Server.Repositories;
 using TechHelper.Services;
-using static TechHelper.Context.AutoMapperProFile;
 
 namespace TechHelper.Server.Services
 {
+
 	public class ExamService : IExamService
 	{
 		private readonly IUnitOfWork _unitOfWork;
-		private readonly IRepository<Assignment> _assignmentRepo;
-		private readonly IRepository<AssignmentGroup> _assignmentGroupRepo;
-		private readonly IRepository<AssignmentQuestion> _assignmentQuestionRepo;
-		private readonly IRepository<Question> _questionRepo;
-		public ExamService(IUnitOfWork unitOfWork, IMapper mapper, UserManager<User> userManager)
+		private readonly IExamRepository _examRepository;
+		private readonly IMapper _mapper;
+
+		public ExamService(IUnitOfWork unitOfWork, IExamRepository examRepository, IMapper mapper)
 		{
 			_unitOfWork = unitOfWork;
+			_examRepository = examRepository;
 			_mapper = mapper;
-			_userManager = userManager;
-
-			_assignmentRepo = _unitOfWork.GetRepository<Assignment>();
-			_assignmentGroupRepo = _unitOfWork.GetRepository<AssignmentGroup>();
-			_assignmentQuestionRepo = _unitOfWork.GetRepository<AssignmentQuestion>();
-			_questionRepo = _unitOfWork.GetRepository<Question>();
 		}
 
-		private readonly IMapper _mapper;
-		private readonly UserManager<User> _userManager;
-
-		public async Task<ApiResponse> AddAsync(ExamDto model)
+		public async Task<ApiResponse> CreateExamAsync(AssignmentDto assignmentDto)
 		{
-			try
+
+			Assignment newAssi = _mapper.Map<Assignment>(assignmentDto);
+
+			await _examRepository.AddAsync(newAssi);
+
+
+			var context =  _unitOfWork.GetDbContext<ApplicationContext>();
+
+			foreach (var entry in context.ChangeTracker.Entries())
 			{
-				var result = await SaveParsedExam(model);
-				if (result.Status)
+				if (entry.State == Microsoft.EntityFrameworkCore.EntityState.Added)
 				{
-					return ApiResponse.Success("保存试题成功");
-				}
-				else
-				{
-					return ApiResponse.Error($"保存试题数据失败{result.Message}");
+					if(entry.Entity is Question newQues)
+					{
+						newQues.CreatorId = newAssi.CreatorId;
+					}
 				}
 
 			}
-			catch (Exception ex)
+
+			await _unitOfWork.SaveChangesAsync();
+
+			return ApiResponse.Success();
+		}
+
+		private async void ParseStruct(AssignmentStructDto assignmentStruct, Guid ParentID)
+		{
+
+			var newStruct = _mapper.Map<AssignmentStruct>(assignmentStruct);
+			newStruct.ParentStructId = Guid.Empty == ParentID ? null : ParentID;
+			await _examRepository.AddAsync(newStruct);
+
+
+			foreach (var item in assignmentStruct.AssignmentQuestions)
 			{
-				return ApiResponse.Error($"保存试题数据失败: {ex.Message}");
+				var newQuestion = _mapper.Map<Question>(item);
+				//newQuestion.ParentQuestionId = item.ParentQuestion == null ? null : item.ParentQuestion.Id;
+				await _examRepository.AddAsync(newQuestion);
+
+				//await ParseAssignmentQuestion(assignmentStruct, item, newQuestion);
 			}
+
+
+			foreach (var item in assignmentStruct.ChildrenGroups)
+			{
+				ParseStruct(item, assignmentStruct.Id);
+			}
+		}
+
+		private async Task ParseAssignmentQuestion(AssignmentStructDto assignmentStruct, QuestionDto item, Question newQuestion)
+		{
+			AssignmentQuestion newAssignQues = new AssignmentQuestion();
+			newAssignQues.QuestionId = newQuestion.Id;
+			newAssignQues.AssignmentStructId = assignmentStruct.Id;
+			newAssignQues.CreatedAt = DateTime.UtcNow;
+			newAssignQues.Score = item.Score;
+			await _examRepository.AddAsync(newAssignQues);
+		}
+
+		private void SetEntityIdsAndRelations(AssignmentStruct group, Guid? assignmentId, Guid creatorId)
+		{
+			group.Id = Guid.NewGuid();
+			group.AssignmentId = assignmentId;
+
+			foreach (var aq in group.AssignmentQuestions)
+			{
+				aq.Id = Guid.NewGuid();
+				aq.AssignmentStructId = group.Id;
+				aq.Question.Id = Guid.NewGuid();
+				aq.Question.CreatorId = creatorId;
+				aq.CreatedAt = DateTime.UtcNow;
+				// ... 其他默认值
+			}
+
+			foreach (var childGroup in group.ChildrenGroups)
+			{
+				// 子题组的 AssignmentId 为 null，通过 ParentGroup 关联
+				SetEntityIdsAndRelations(childGroup, null, creatorId);
+				childGroup.ParentStructId = group.Id;
+			}
+		}
+
+		public async Task<AssignmentDto> GetExamByIdAsync(Guid id)
+		{
+			var assignment = await _examRepository.GetFullExamByIdAsync(id);
+			if (assignment == null)
+			{
+
+				throw new InvalidOperationException("");
+			}
+
+			return _mapper.Map<AssignmentDto>(assignment);
+		}
+
+		public async Task<IEnumerable<AssignmentDto>> GetAllExamPreviewsAsync(Guid userId)
+		{
+			var assignments = await _examRepository.GetExamPreviewsByUserAsync(userId);
+			return _mapper.Map<IEnumerable<AssignmentDto>>(assignments);
+		}
+
+
+		public Task<ApiResponse> GetAllAsync(QueryParameter query)
+		{
+			throw new NotImplementedException();
+		}
+
+		public Task<ApiResponse> GetAsync(Guid id)
+		{
+			throw new NotImplementedException();
+		}
+
+		public Task<ApiResponse> AddAsync(AssignmentDto model)
+		{
+			throw new NotImplementedException();
+		}
+
+		public Task<ApiResponse> UpdateAsync(AssignmentDto model)
+		{
+			throw new NotImplementedException();
 		}
 
 		public Task<ApiResponse> DeleteAsync(Guid id)
@@ -58,392 +151,10 @@ namespace TechHelper.Server.Services
 			throw new NotImplementedException();
 		}
 
-		public Task<ApiResponse> GetAllAsync(QueryParameter query)
+		Task<ApiResponse> IExamService.GetAllExamPreviewsAsync(Guid userId)
 		{
 			throw new NotImplementedException();
 		}
-
-		public async Task<ApiResponse> GetAsync(Guid id)
-		{
-			try
-			{
-				var result = await GetExamByIdAsync(id);
-				return result;
-
-			}
-			catch (Exception ex)
-			{
-				return ApiResponse.Error($"获取试题数据失败: {ex.Message}");
-			}
-		}
-
-		public Task<ApiResponse> UpdateAsync(ExamDto model)
-		{
-			throw new NotImplementedException();
-		}
-
-
-		public async Task<IEnumerable<AssignmentGroup>> LoadFullGroupTree(Guid rootGroupId)
-		{
-			var query = @"
-        WITH RECURSIVE GroupTree AS (
-            SELECT 
-                ag.*, 
-                CAST(ag.`number` AS CHAR(255)) AS path
-            FROM assignment_group ag 
-            WHERE ag.id = @rootId
-            
-            UNION ALL
-            
-            SELECT 
-                c.*, 
-                CONCAT(ct.path, '.', c.`number`)
-            FROM assignment_group c
-            INNER JOIN GroupTree ct ON c.parent_group = ct.id
-        )
-        SELECT * FROM GroupTree ORDER BY path;
-    ";
-
-			// 执行查询
-			var groups = await _unitOfWork.GetRepository<AssignmentGroup>()
-				.FromSql(query, new MySqlParameter("rootId", rootGroupId))
-				.ToListAsync();
-
-			// 内存中构建树结构
-			var groupDict = groups.ToDictionary(g => g.Id);
-			var root = groupDict[rootGroupId];
-
-			foreach (var group in groups)
-			{
-				if (group.ParentGroup != null && groupDict.TryGetValue(group.ParentGroup.Value, out var parent))
-				{
-					parent.ChildAssignmentGroups ??= new List<AssignmentGroup>();
-					parent.ChildAssignmentGroups.Add(group);
-				}
-			}
-
-			return new List<AssignmentGroup> { root };
-		}
-
-		public async Task LoadRecursiveAssignmentGroups(IEnumerable<AssignmentGroup> groups)
-		{
-			foreach (var group in groups.ToList())
-			{
-
-				var loadedGroup = await _unitOfWork.GetRepository<AssignmentGroup>()
-					.GetFirstOrDefaultAsync(
-						predicate: ag => ag.Id == group.Id,
-						include: source => source
-							.Include(ag => ag.AssignmentQuestions.Where(aq => !aq.IsDeleted))
-								.ThenInclude(aq => aq.Question)
-							.Include(ag => ag.ChildAssignmentGroups)
-					);
-
-				if (loadedGroup == null) continue;
-
-				group.ChildAssignmentGroups = loadedGroup.ChildAssignmentGroups;
-				group.AssignmentQuestions = loadedGroup.AssignmentQuestions;
-
-				if (group.ChildAssignmentGroups is { Count: > 0 })
-				{
-					await LoadRecursiveAssignmentGroups(group.ChildAssignmentGroups);
-				}
-			}
-		}
-
-		public async Task<ApiResponse> GetExamByIdAsync(Guid assignmentId)
-		{
-			try
-			{
-				var assignment = await _unitOfWork.GetRepository<Assignment>().GetFirstOrDefaultAsync(
-					predicate: a => a.Id == assignmentId && !a.IsDeleted);
-
-				if (assignment == null)
-				{
-					return ApiResponse.Error($"找不到 ID 为 {assignmentId} 的试卷。");
-				}
-
-
-
-				// 获取所有相关题组和题目，并过滤掉已删除的
-				var allGroups = await _unitOfWork.GetRepository<AssignmentGroup>().GetFirstOrDefaultAsync(
-					predicate: ag => ag.AssignmentId == assignmentId && !ag.IsDeleted,
-					include: source => source
-					.Include(ag => ag.ChildAssignmentGroups)
-				);
-				await LoadRecursiveAssignmentGroups(allGroups.ChildAssignmentGroups);
-
-				if (allGroups == null || !allGroups.ChildAssignmentGroups.Any())
-				{
-					// 试卷存在但没有内容，返回一个空的 ExamDto
-					return ApiResponse.Success("试卷没有内容。", new ExamDto
-					{
-						AssignmentId = assignment.Id,
-						AssignmentTitle = assignment.Title,
-						Description = assignment.Description,
-						SubjectArea = assignment.Submissions.ToString()
-					});
-				}
-
-				var rootGroups = allGroups.ChildAssignmentGroups.ToList();
-
-				var rootqg = new QuestionGroupDto();
-
-				foreach (var ag in rootGroups.OrderBy(g => g.Number))
-				{
-					var agDto = MapAssignmentGroupToDto(ag);
-					rootqg.SubQuestionGroups.Add(agDto);
-				}
-
-
-				// 递归映射到 ExamDto
-				var examDto = new ExamDto
-				{
-					AssignmentId = assignment.Id,
-					AssignmentTitle = assignment.Title,
-					Description = assignment.Description,
-					SubjectArea = assignment.Submissions.ToString(),
-					QuestionGroups = rootqg
-				};
-
-				return ApiResponse.Success("试卷信息已成功获取。", examDto);
-			}
-			catch (Exception ex)
-			{
-				return ApiResponse.Error($"获取试卷时发生错误: {ex.Message}", ex);
-			}
-		}
-
-
-		public QuestionGroupDto MapAssignmentGroupToDto(AssignmentGroup ag)
-		{
-			// 创建当前节点的DTO
-			var dto = new QuestionGroupDto
-			{
-				Title = ag.Title,
-				Score = (int)(ag.TotalPoints ?? 0),
-				Descript = ag.Descript,
-				SubQuestions = ag.AssignmentQuestions?
-					.OrderBy(aq => aq.QuestionNumber)
-					.Select(aq => new SubQuestionDto
-					{
-						Index = aq.QuestionNumber,
-						Stem = aq.Question?.QuestionText,
-						Score = aq.Score ?? 0,
-						SampleAnswer = aq.Question?.CorrectAnswer,
-						QuestionType = aq.Question?.QuestionType.ToString(),
-						DifficultyLevel = aq.Question?.DifficultyLevel.ToString(),
-						Options = new List<OptionDto>() // 根据需要初始化
-					}).ToList() ?? new List<SubQuestionDto>(),
-				SubQuestionGroups = new List<QuestionGroupDto>() // 初始化子集合
-			};
-
-			// 递归处理子组
-			if (ag.ChildAssignmentGroups != null && ag.ChildAssignmentGroups.Count > 0)
-			{
-				foreach (var child in ag.ChildAssignmentGroups.OrderBy(c => c.Number))
-				{
-					var childDto = MapAssignmentGroupToDto(child); // 递归获取子DTO
-					dto.SubQuestionGroups.Add(childDto); // 添加到当前节点的子集合
-				}
-			}
-
-			return dto;
-		}
-
-		private List<QuestionGroupDto> MapAssignmentGroupsToDto2(
-		List<AssignmentGroup> currentLevelGroups,
-		IEnumerable<AssignmentGroup> allFetchedGroups)
-		{
-			var dtos = new List<QuestionGroupDto>();
-
-			foreach (var group in currentLevelGroups.OrderBy(g => g.Number))
-			{
-				var groupDto = new QuestionGroupDto
-				{
-
-					Title = group.Title,
-					Score = (int)(group.TotalPoints ?? 0),
-					Descript = group.Descript,
-					SubQuestions = group.AssignmentQuestions
-										.OrderBy(aq => aq.QuestionNumber)
-										.Select(aq => new SubQuestionDto
-										{
-											Index = aq.QuestionNumber,
-											Stem = aq.Question.QuestionText,
-											Score = aq.Score ?? 0,
-											SampleAnswer = aq.Question.CorrectAnswer,
-											QuestionType = aq.Question.QuestionType.ToString(),
-											DifficultyLevel = aq.Question.DifficultyLevel.ToString(),
-											Options = new List<OptionDto>()
-										}).ToList(),
-					// 递归映射子题组
-					SubQuestionGroups = MapAssignmentGroupsToDto2(
-						allFetchedGroups.Where(ag => ag.ParentGroup == group.Id && !ag.IsDeleted).ToList(),
-						allFetchedGroups)
-				};
-				dtos.Add(groupDto);
-			}
-			return dtos;
-		}
-
-		public async Task<TechHelper.Services.ApiResponse> SaveParsedExam(ExamDto examData)
-		{
-			// 获取当前登录用户
-			var currentUser = await _userManager.FindByEmailAsync(examData.CreaterEmail);
-			if (currentUser == null)
-			{
-				return ApiResponse.Error("未找到当前登录用户，无法保存试题。");
-			}
-			var currentUserId = currentUser.Id;
-
-			try
-			{
-				Guid assignmentId;
-
-				// 创建新的 Assignment 实体
-				var newAssignment = new Assignment
-				{
-					Id = Guid.NewGuid(),
-					Title = examData.AssignmentTitle,
-					Description = examData.Description,
-					SubjectArea = examData.SubjectArea,
-					CreatedAt = DateTime.UtcNow,
-					CreatedBy = currentUserId,
-					IsDeleted = false
-				};
-				await _assignmentRepo.InsertAsync(newAssignment);
-				assignmentId = newAssignment.Id;
-
-
-				// 从 ExamDto.QuestionGroups 获取根题组。
-				// 确保只有一个根题组，因为您的模型是“试卷只有一个根节点”。
-				if (examData.QuestionGroups == null)
-				{
-					throw new ArgumentException("试卷必须包含且只能包含一个根题组。");
-				}
-
-				await ProcessAndSaveAssignmentGroupsRecursive(
-					examData.QuestionGroups,
-					examData.SubjectArea.ToString(),
-					assignmentId,
-					null, // 根题组没有父级
-					currentUserId);
-
-				if (await _unitOfWork.SaveChangesAsync() > 0)
-				{
-					return ApiResponse.Success("试卷数据已成功保存。", new ExamDto { AssignmentId = assignmentId, AssignmentTitle = examData.AssignmentTitle });
-				}
-				else
-				{
-					return ApiResponse.Success("没有新的试卷数据需要保存。");
-				}
-			}
-			catch (Exception ex)
-			{
-				return ApiResponse.Error($"保存试卷数据失败: {ex.Message}", ex);
-			}
-		}
-
-		private async Task ProcessAndSaveAssignmentGroupsRecursive(
-			QuestionGroupDto qgDto,
-			string subjectarea,
-			Guid assignmentId,
-			Guid? parentAssignmentGroupId,
-			Guid createdById)
-		{
-			if (qgDto.ValidQuestionGroup)
-			{
-				await SaveQuestionGroup(qgDto);
-			}
-			else
-			{
-				byte groupNumber = 1;
-
-
-				var newAssignmentGroup = new AssignmentGroup
-				{
-					Id = Guid.NewGuid(), // 后端生成 GUID
-					Title = qgDto.Title,
-					Descript = qgDto.Descript,
-					TotalPoints = qgDto.Score,
-					Number = (byte)qgDto.Index,
-					ValidQuestionGroup = qgDto.ValidQuestionGroup,
-					ParentGroup = parentAssignmentGroupId,
-					AssignmentId = parentAssignmentGroupId == null ? assignmentId : (Guid?)null,
-					IsDeleted = false
-				};
-				await _unitOfWork.GetRepository<AssignmentGroup>().InsertAsync(newAssignmentGroup);
-
-				// 处理子题目
-				uint questionNumber = 1;
-				foreach (var sqDto in qgDto.SubQuestions.OrderBy(s => s.Index))
-				{
-					var newQuestion = _mapper.Map<Question>(sqDto);
-					newQuestion.Id = Guid.NewGuid();
-					newQuestion.CreatedBy = createdById;
-					newQuestion.CreatedAt = DateTime.UtcNow;
-					newQuestion.UpdatedAt = DateTime.UtcNow;
-					newQuestion.IsDeleted = false;
-					newQuestion.SubjectArea = EnumMappingHelpers.ParseEnumSafe(subjectarea, SubjectAreaEnum.Unknown);
-
-					await _unitOfWork.GetRepository<Question>().InsertAsync(newQuestion);
-
-					var newAssignmentQuestion = new AssignmentQuestion
-					{
-						Id = Guid.NewGuid(),
-						QuestionId = newQuestion.Id,
-						QuestionNumber = (byte)questionNumber,
-						AssignmentGroupId = newAssignmentGroup.Id,
-						Score = sqDto.Score,
-						IsDeleted = false,
-						CreatedAt = DateTime.UtcNow
-					};
-					await _unitOfWork.GetRepository<AssignmentQuestion>().InsertAsync(newAssignmentQuestion);
-
-					questionNumber++;
-				}
-
-
-
-				// 递归处理子题组
-				// 这里需要遍历 SubQuestionGroups，并对每个子组进行递归调用
-				foreach (var subQgDto in qgDto.SubQuestionGroups.OrderBy(s => s.Index))
-				{
-					await ProcessAndSaveAssignmentGroupsRecursive(
-						subQgDto, // 传入当前的子题组 DTO
-						subjectarea,
-						assignmentId, // 顶层 AssignmentId 依然传递下去，但子组不会直接使用它
-						newAssignmentGroup.Id, // 将当前题组的 ID 作为下一层递归的 parentAssignmentGroupId
-						createdById);
-				}
-			}
-		}
-
-		private async Task SaveQuestionGroup(QuestionGroupDto qgDto)
-		{
-			
-		}
-
-		public async Task<ApiResponse> GetAllExamPreview(Guid user)
-		{
-			try
-			{
-				var assignments = await _unitOfWork.GetRepository<Assignment>().GetAllAsync(
-					predicate: a => a.CreatedBy == user && !a.IsDeleted);
-
-				if (assignments.Any())
-				{
-					var exam = _mapper.Map<IEnumerable<ExamDto>>(assignments);
-					return ApiResponse.Success(result: exam);
-				}
-
-				return ApiResponse.Error("你还没有创建任何试卷");
-			}
-			catch (Exception ex)
-			{
-				return ApiResponse.Error($"查询出了一点问题 , 详细信息为: {ex.Message}, 请稍后再试");
-			}
-		}
 	}
+
 }
diff --git a/TechHelper.Server/Services/ExamService2.cs b/TechHelper.Server/Services/ExamService2.cs
deleted file mode 100644
index a679c9b..0000000
--- a/TechHelper.Server/Services/ExamService2.cs
+++ /dev/null
@@ -1,123 +0,0 @@
-using AutoMapper;
-using Entities.Contracts;
-using Entities.DTO;
-using SharedDATA.Api;
-using TechHelper.Server.Repository;
-using TechHelper.Services;
-
-namespace TechHelper.Server.Services
-{
-
-	public class ExamService2 : IExamService2
-	{
-		private readonly IUnitOfWork _unitOfWork;
-		private readonly IExamRepository _examRepository;
-		private readonly IMapper _mapper;
-
-		public ExamService2(IUnitOfWork unitOfWork, IExamRepository examRepository, IMapper mapper)
-		{
-			_unitOfWork = unitOfWork;
-			_examRepository = examRepository;
-			_mapper = mapper;
-		}
-
-		public async Task<Guid> CreateExamAsync(ExamDto examDto, Guid creatorId)
-		{
-			if (examDto.QuestionGroups == null)
-			{
-				throw new ArgumentException("试卷必须包含一个根题组。");
-			}
-
-			// 使用 AutoMapper 将 DTO 映射到实体
-			var assignment = _mapper.Map<Assignment>(examDto);
-
-			// 设置后端生成的属性
-			assignment.Id = Guid.NewGuid();
-			assignment.CreatedBy = creatorId;
-			assignment.CreatedAt = DateTime.UtcNow;
-
-			// 递归设置所有子实体的ID和关联关系
-			SetEntityIdsAndRelations(assignment.AssignmentGroups.First(), assignment.Id, creatorId);
-
-			await _examRepository.AddAsync(assignment);
-			await _unitOfWork.SaveChangesAsync();
-
-			return assignment.Id;
-		}
-
-		private void SetEntityIdsAndRelations(AssignmentGroup group, Guid? assignmentId, Guid creatorId)
-		{
-			group.Id = Guid.NewGuid();
-			group.AssignmentId = assignmentId;
-
-			foreach (var aq in group.AssignmentQuestions)
-			{
-				aq.Id = Guid.NewGuid();
-				aq.AssignmentGroupId = group.Id;
-				aq.Question.Id = Guid.NewGuid();
-				aq.Question.CreatedBy = creatorId;
-				aq.CreatedAt = DateTime.UtcNow;
-				// ... 其他默认值
-			}
-
-			foreach (var childGroup in group.ChildAssignmentGroups)
-			{
-				// 子题组的 AssignmentId 为 null，通过 ParentGroup 关联
-				SetEntityIdsAndRelations(childGroup, null, creatorId);
-				childGroup.ParentGroup = group.Id;
-			}
-		}
-
-		public async Task<ExamDto> GetExamByIdAsync(Guid id)
-		{
-			var assignment = await _examRepository.GetFullExamByIdAsync(id);
-			if (assignment == null)
-			{
-
-				throw new InvalidOperationException("");
-			}
-
-			return _mapper.Map<ExamDto>(assignment);
-		}
-
-		public async Task<IEnumerable<ExamDto>> GetAllExamPreviewsAsync(Guid userId)
-		{
-			var assignments = await _examRepository.GetExamPreviewsByUserAsync(userId);
-			return _mapper.Map<IEnumerable<ExamDto>>(assignments);
-		}
-
-		public async Task AddAsync(QuestionGroupDto qg)
-		{
-			if (qg.ValidQuestionGroup)
-			{
-				var mapQG = _mapper.Map<QuestionGroup>(qg);
-			}
-		}
-
-		public Task<ApiResponse> GetAllAsync(QueryParameter query)
-		{
-			throw new NotImplementedException();
-		}
-
-		public Task<ApiResponse> GetAsync(Guid id)
-		{
-			throw new NotImplementedException();
-		}
-
-		public Task<ApiResponse> AddAsync(ExamDto model)
-		{
-			throw new NotImplementedException();
-		}
-
-		public Task<ApiResponse> UpdateAsync(ExamDto model)
-		{
-			throw new NotImplementedException();
-		}
-
-		public Task<ApiResponse> DeleteAsync(Guid id)
-		{
-			throw new NotImplementedException();
-		}
-	}
-
-}
diff --git a/TechHelper.Server/Services/IAssignmentGroupService.cs b/TechHelper.Server/Services/IAssignmentGroupService.cs
index 685b281..af99867 100644
--- a/TechHelper.Server/Services/IAssignmentGroupService.cs
+++ b/TechHelper.Server/Services/IAssignmentGroupService.cs
@@ -3,7 +3,7 @@ using TechHelper.Services;
 
 namespace TechHelper.Server.Services
 {
-	public interface IAssignmentGroupService : IBaseService<AssignmentGroup, Guid>
+	public interface IAssignmentGroupService : IBaseService<AssignmentStruct, Guid>
 	{
 	}
 }
diff --git a/TechHelper.Server/Services/IExamService.cs b/TechHelper.Server/Services/IExamService.cs
index ef29d9a..ec4ba55 100644
--- a/TechHelper.Server/Services/IExamService.cs
+++ b/TechHelper.Server/Services/IExamService.cs
@@ -4,9 +4,23 @@ using TechHelper.Services;
 
 namespace TechHelper.Server.Services
 {
-	public interface IExamService : IBaseService<ExamDto, Guid>
+	public interface IExamService : IBaseService<AssignmentDto, Guid>
 	{
-		Task<ApiResponse> GetAllExamPreview(Guid user);
-		QuestionGroupDto MapAssignmentGroupToDto(AssignmentGroup ag);
+		/// <summary>
+		/// 根据 ID 获取试卷 DTO。
+		/// </summary>
+		Task<AssignmentDto> GetExamByIdAsync(Guid id);
+
+		/// <summary>
+		/// 获取指定用户的所有试卷预览。
+		/// </summary>
+		Task<ApiResponse> GetAllExamPreviewsAsync(Guid userId);
+
+		/// <summary>
+		/// 创建一个新的试卷。
+		/// </summary>
+		/// <returns>创建成功的试卷ID</returns>
+		Task<ApiResponse> CreateExamAsync(AssignmentDto examDto);
+
 	}
 }
diff --git a/TechHelper.Server/Services/IExamService2.cs b/TechHelper.Server/Services/IExamService2.cs
deleted file mode 100644
index 7836722..0000000
--- a/TechHelper.Server/Services/IExamService2.cs
+++ /dev/null
@@ -1,26 +0,0 @@
-using Entities.Contracts;
-using Entities.DTO;
-using TechHelper.Services;
-
-namespace TechHelper.Server.Services
-{
-	public interface IExamService2 : IBaseService<ExamDto, Guid>
-	{
-		/// <summary>
-		/// 根据 ID 获取试卷 DTO。
-		/// </summary>
-		Task<ExamDto> GetExamByIdAsync(Guid id);
-
-		/// <summary>
-		/// 获取指定用户的所有试卷预览。
-		/// </summary>
-		Task<IEnumerable<ExamDto>> GetAllExamPreviewsAsync(Guid userId);
-
-		/// <summary>
-		/// 创建一个新的试卷。
-		/// </summary>
-		/// <returns>创建成功的试卷ID</returns>
-		Task<Guid> CreateExamAsync(ExamDto examDto, Guid creatorId);
-
-	}
-}
diff --git a/TechHelper.Server/Services/IQuestionGroupService.cs b/TechHelper.Server/Services/IQuestionGroupService.cs
deleted file mode 100644
index 65e69aa..0000000
--- a/TechHelper.Server/Services/IQuestionGroupService.cs
+++ /dev/null
@@ -1,9 +0,0 @@
-using Entities.Contracts;
-using TechHelper.Services;
-
-namespace TechHelper.Server.Services
-{
-	public interface IQuestionGroupService : IBaseService<QuestionGroup, Guid>
-	{
-	}
-}
diff --git a/TechHelper.Server/Services/QuestionGroupService.cs b/TechHelper.Server/Services/QuestionGroupService.cs
deleted file mode 100644
index a200b26..0000000
--- a/TechHelper.Server/Services/QuestionGroupService.cs
+++ /dev/null
@@ -1,66 +0,0 @@
-using AutoMapper;
-using Entities.Contracts;
-using Entities.DTO;
-using SharedDATA.Api;
-using TechHelper.Services;
-
-namespace TechHelper.Server.Services
-{
-	public class QuestionGroupService : IAssignmentGroupService
-	{
-
-		private readonly IUnitOfWork _work;
-		// 如果不再需要 AutoMapper 进行实体到 DTO 的映射，可以移除 _mapper 字段
-		// 但如果 AutoMapper 在其他服务中用于其他映射，或者将来可能需要，可以保留
-		private readonly IMapper _mapper;
-		private readonly IExamService _examService;
-
-		public QuestionGroupService(IUnitOfWork work, IMapper mapper, IExamService examService)
-		{
-			_work = work;
-			_mapper = mapper;
-			_examService = examService;
-		}
-
-
-		public Task<ApiResponse> AddAsync(AssignmentGroup model)
-		{
-			throw new NotImplementedException();
-		}
-
-		public Task<ApiResponse> DeleteAsync(Guid id)
-		{
-			throw new NotImplementedException();
-		}
-
-		public Task<ApiResponse> GetAllAsync(QueryParameter query)
-		{
-			throw new NotImplementedException();
-		}
-
-		public async Task<ApiResponse> GetAsync(Guid id)
-		{
-			try
-			{
-
-				var result = await _work.GetRepository<AssignmentGroup>().GetFirstOrDefaultAsync(predicate: ag => ag.Id == id);
-				QuestionGroupDto qgd = new QuestionGroupDto();
-				if (result != null)
-				{
-					qgd = _examService.MapAssignmentGroupToDto(result);
-					return ApiResponse.Success(result: qgd);
-				}
-				return ApiResponse.Error("没找到问题组");
-			}
-			catch (Exception ex)
-			{
-				return ApiResponse.Error($"出现了一点问题: {ex.Message}");
-			}
-		}
-
-		public Task<ApiResponse> UpdateAsync(AssignmentGroup model)
-		{
-			throw new NotImplementedException();
-		}
-	}
-}
diff --git a/TechHelper.Server/Services/QuestionService.cs b/TechHelper.Server/Services/QuestionService.cs
index cdba5a6..ba9a35a 100644
--- a/TechHelper.Server/Services/QuestionService.cs
+++ b/TechHelper.Server/Services/QuestionService.cs
@@ -31,12 +31,12 @@ namespace TechHelper.Server.Services
 			{
 				// 可以在此处进行业务逻辑校验，例如检查题目是否已存在
 				var existingQuestion = await _work.GetRepository<Question>().GetFirstOrDefaultAsync(
-					predicate: q => q.QuestionText == model.QuestionText && !q.IsDeleted
+					predicate: q => q.Title == model.Title && !q.IsDeleted
 				);
 
 				if (existingQuestion != null)
 				{
-					return ApiResponse.Error($"题目 '{model.QuestionText}' 已存在，请勿重复添加。");
+					return ApiResponse.Error($"题目 '{model.Title}' 已存在，请勿重复添加。");
 				}
 
 				// 设置创建时间、创建者等通用属性
@@ -44,8 +44,7 @@ namespace TechHelper.Server.Services
 				model.CreatedAt = DateTime.UtcNow;
 				model.UpdatedAt = DateTime.UtcNow;
 				model.IsDeleted = false;
-				model.ValidQuestion = true; // 假设新添加的题目默认为有效
-											// model.CreatedBy = ... // 实际应用中，这里应该从当前用户上下文获取
+
 
 				await _work.GetRepository<Question>().InsertAsync(model);
 				await _work.SaveChangesAsync();
@@ -90,7 +89,7 @@ namespace TechHelper.Server.Services
 			try
 			{
 				var question = await _work.GetRepository<Question>().GetFirstOrDefaultAsync(
-					predicate: q => q.QuestionText == title && !q.IsDeleted
+					predicate: q => q.Title == title && !q.IsDeleted
 				);
 
 				if (question == null)
@@ -119,10 +118,10 @@ namespace TechHelper.Server.Services
 				var distinctTitles = titles.Distinct(StringComparer.OrdinalIgnoreCase).ToList();
 
 				var existingQuestions = await _work.GetRepository<Question>().GetAllAsync(
-					predicate: q => distinctTitles.Contains(q.QuestionText) && !q.IsDeleted
+					predicate: q => distinctTitles.Contains(q.Title) && !q.IsDeleted
 				);
 
-				var existingQuestionTexts = new HashSet<string>(existingQuestions.Select(q => q.QuestionText), StringComparer.OrdinalIgnoreCase);
+				var existingQuestionTexts = new HashSet<string>(existingQuestions.Select(q => q.Title), StringComparer.OrdinalIgnoreCase);
 
 				var resultDictionary = new Dictionary<string, bool>(StringComparer.OrdinalIgnoreCase);
 				foreach (var title in titles)
@@ -146,7 +145,7 @@ namespace TechHelper.Server.Services
 
 				if (!string.IsNullOrWhiteSpace(query.Search))
 				{
-					predicate = predicate.And(q => q.QuestionText.Contains(query.Search));
+					predicate = predicate.And(q => q.Title.Contains(query.Search));
 				}
 
 				Func<IQueryable<Question>, IOrderedQueryable<Question>> orderBy = null;
@@ -214,12 +213,12 @@ namespace TechHelper.Server.Services
 
 				// 检查更新后的题目文本是否与现有其他题目重复
 				var duplicateCheck = await _work.GetRepository<Question>().GetFirstOrDefaultAsync(
-					predicate: q => q.Id != model.Id && q.QuestionText == model.QuestionText && !q.IsDeleted
+					predicate: q => q.Id != model.Id && q.Title == model.Title && !q.IsDeleted
 				);
 
 				if (duplicateCheck != null)
 				{
-					return ApiResponse.Error($"题目文本 '{model.QuestionText}' 已被其他题目占用，请修改。");
+					return ApiResponse.Error($"题目文本 '{model.Title}' 已被其他题目占用，请修改。");
 				}
 
 				// 手动复制属性或使用 AutoMapper (如果保留了 _mapper 字段)
diff --git a/TechHelper.Server/TechHelper.Server.csproj b/TechHelper.Server/TechHelper.Server.csproj
index a0fab5e..407c0f9 100644
--- a/TechHelper.Server/TechHelper.Server.csproj
+++ b/TechHelper.Server/TechHelper.Server.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk.Web">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
diff --git a/TechHelper.Server/appsettings.json b/TechHelper.Server/appsettings.json
index f0871d6..3e21c47 100644
--- a/TechHelper.Server/appsettings.json
+++ b/TechHelper.Server/appsettings.json
@@ -6,7 +6,7 @@
     }
   },
   "ConnectionStrings": {
-    "XSDB": "Server=mysql.eazygame.cn;Port=13002;Database=test;User=root;Password=wx1998WX"
+    "XSDB": "Server=mysql.eazygame.cn;Port=13002;Database=test1;User=root;Password=wx1998WX"
   },
   "JWTSettings": {
     "securityKey": "MxcxQHVYVDQ0U3lqWkIwdjZlSGx4eFp6YnFpUGxodmc5Y3hPZk5vWm9MZEg2Y0I=",