标签：oid uil ati str context ext class hone 需要
1、定义模型
示例：学生和桌子的一对一关系：每个学生需要对应一个桌位信息，桌位信息不用包含学生信息
public class Desk { public int Id { get; set; } public string Name { get; set; } public Student Student { get; set; } }
public class Student { public int Id { get; set; } public string Name { get; set; } public int DeskID { get; set; } public Desk Desk { get; set; } }
在Student中定义 DeskID和Desk模型，在Desk表中定义Student模型
2、在DataContext中定义两者的关系
protected override void OnModelCreating(ModelBuilder modelBuilder) { // Do：一对一关系模型 modelBuilder.Entity<Student>().HasOne(l => l.Desk).WithOne(l => l.Student) .HasForeignKey<Student>(l => l.DeskID); }
public DbSet<Student> Students { get; set; }
public DbSet<Desk> Desks { get; set; }
此时通过迁移命令将会生成Students表和Desks表
1、定义模型
示例：学校和老师的一对多关系：一个学校对应多个老师，一个老师对应一个学校
public class School { public int Id { get; set; } public string Name { get; set; } public List<Teacher> Teachers { get; set; } }
public class Teacher { public int Id { get; set; } public string Name { get; set; } public int SchoolID { get; set; } public School School { get; set; } }
2、在DataContext中定义两者的关系
protected override void OnModelCreating(ModelBuilder modelBuilder) { // Do：一对多关系模型 modelBuilder.Entity<Teacher>().HasOne(l => l.School).WithMany(l => l.Teachers) .HasForeignKey(l => l.SchoolID); } public DbSet<Teacher> Teachers { get; set; } public DbSet<School> Schools { get; set; }
此时通过迁移命令将会生成Schools表和Teachers表
五、多对多的关系模型
1、定义模型：
示例：建立父母和孩子的多对多模型，父母可以对应多个孩子，孩子可以有父亲，母亲的对应关系
// Do：定义父母类型 public class Parent { public Parent() { this.RelationShips =new List<RelationShip>(); } public int Id { get; set; } public string Name { get; set; } // Do：3、定义关系集合 public List<RelationShip> RelationShips { get; set; } }
// Do：定义子类型 public class Child { public Child() { this.RelationShips=new List<RelationShip>(); } public int Id { get; set; } public string Name { get; set; } // Do：2、定义关系集合 public List<RelationShip> RelationShips { get; set; } }
/// <summary> /// 1、多对多关系模型 /// </summary> public class RelationShip { public int ChildID { get; set; } public Child Child { get; set; } public int ParentID { get; set; } public Parent Parent { get; set; } }
2、在DataContext中定义两者的关系
protected override void OnModelCreating(ModelBuilder modelBuilder) { // Do：多对多配置联合主键 modelBuilder.Entity<RelationShip>().HasKey(l => new {l.ChildID, l.ParentID}); // Do：多对多定义关系模型映射（本段代码可有可无） modelBuilder.Entity<RelationShip>().HasOne(l => l.Child).WithMany(l => l.RelationShips) .HasForeignKey(l => l.ChildID); modelBuilder.Entity<RelationShip>().HasOne(l => l.Parent).WithMany(l => l.RelationShips) .HasForeignKey(l => l.ParentID); } public DbSet<Teacher> Teachers { get; set; } public DbSet<School> Schools { get; set; }
标签：oid uil ati str context ext class hone 需要
原文地址：https://www.cnblogs.com/ZaraNet/p/12409156.html
