添加项目文件。

Entities/Contracts/AssignmentClass.cs

@@ -0,0 +1,36 @@
+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("assignment_class")]
+	public class AssignmentClass
+	{
+		[Key]
+		[Column("assignment_id", Order = 0)]
+		[ForeignKey("Assignment")]
+		public Guid AssignmentId { get; set; }
+
+		[Key]
+		[Column("class_id", Order = 1)]
+		[ForeignKey("Class")]
+		public Guid ClassId { get; set; }
+
+		[Column("assigned_at")]
+		public DateTime AssignedAt { get; set; }
+
+		[Column("deleted")]
+		public bool IsDeleted { get; set; }
+
+		// Navigation Properties
+		public Assignment Assignment { get; set; }
+		public Class Class { get; set; }
+
+
+	}
+}