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 List
    
      Students { 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 List
    
      StudentTeacherRelationships { 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 List
    
      StudentTeacherRelationships { 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：

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:nmodelBuilder.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);
     
    

示例代码