基本数据结构
表设计如下：
入学记录
public class AdmissionRecord
{
[Key]
public long Id { get; set; }
public DateTime AdmissionTime { get; set; }
public string Remark { get; set; }
}班级
public class Class
{
[Key]
public long Id { get; set; }
public DateTime CreationTime { get; set; }
public string ClassName { get; set; }
public virtual ListStudents { get; set; }
}学生-教师关系表
public class StudentTeacherRelationship
{
[Key]
public long Id { get; set; }
public long StudentId { get; set; }
public virtual Student Student { get; set; }
public long TeacherId { get; set; }
public virtual Teacher Teacher { get; set; }
}教师
public class Teacher
{
[Key]
public long Id { get; set; }
public string Name { get; set; }
public string TeacherId { get; set; }
public virtual ListStudentTeacherRelationships { get; set; }
}学生
public class Student
{
[Key]
public long Id { get; set; }
public string StudentId { get; set; }
public string Name { get; set; }
public long AdmissionRecordId { get; set; }
//Student-AdmissionRecord 1:1
[ForeignKey("AdmissionRecordId")]
public virtual AdmissionRecord AdmissionRecord { get; set; }
public long ClassId { get; set; }
public virtual Class Class { get; set; }
public virtual ListStudentTeacherRelationships { get; set; }
}一对一
学生-入学记录
public long AdmissionRecordId { get; set; }
//Student-AdmissionRecord 1:1
[ForeignKey("AdmissionRecordId")]
public virtual AdmissionRecord AdmissionRecord { get; set; }另解
modelBuilder.Entity() .HasOne(p => p.AdmissionRecord) .WithOne(p => p.Student) .HasForeignKey(p => p.AdmissionRecordId);
参考资料：
Configuring One To One Relationships In Entity Framework Core
一对多
学生-班级
modelBuilder.Entity() .HasMany(p => p.Students) .WithOne(p => p.Class) .HasForeignKey(p => p.ClassId) .OnDelete(DeleteBehavior.ClientSetNull); //下面写法也可以 //modelBuilder.Entity() // .HasOne(p => p.Class) // .WithMany(p=>p.Students) // .HasForeignKey(k => k.ClassId) // .OnDelete(DeleteBehavior.ClientSetNull);
多对多
学生-教师
//通过StudentTeacherRelationship中间表，通过实现两个1:n，实现m:n modelBuilder.Entity() .HasOne(p => p.Student) .WithMany(p => p.StudentTeacherRelationships) .HasForeignKey(k => k.StudentId) .OnDelete(DeleteBehavior.ClientSetNull); modelBuilder.Entity() .HasOne(p => p.Teacher) .WithMany(p => p.StudentTeacherRelationships) .HasForeignKey(k => k.TeacherId) .OnDelete(DeleteBehavior.ClientSetNull);
