FluentAPI详细用法

  • 设置主键
    modelBuilder.Entity<x>().HasKey(t => t.Name);
  • 设置联合主键
    modelBuilder.Entity<x>().HasKey(t =>new{t.Name,t.ID} );
  • 取消数据库字段标识(取消自动增长)
    modelBuilder.Entity<x>().Property(t=>t.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
  • 设置数据库字段标识(自动增长)
    modelBuilder.Entity<Teacher>().Property(t =>t.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
  • 设置字段最大长度
    modelBuilder.Entity<ClassA>().Property(t => t.Name).HasMaxLength(100);
  • 设置字段为必需
    modelBuilder.Entity<ClassA>().Property(t =>t.Id).IsRequired();
  • 属性不映射到数据库
    modelBuilder.Entity<ClassA>().Ignore(t => t.A);
  • 将属性指定数据库列名:
    modelBuilder.Entity<ClassA>() .Property(t => t.A) .HasColumnName("A_a");
  • 级联删除(数据库默认是不级联删除的)
    modelBuilder.Entity<Course>().HasRequired(t => t.Department).WithMany(t => t.Courses).HasForeignKey(d => d.DepartmentID).WillCascadeOnDelete();
  • 设置为Timestamp
    modelBuilder.Entity<OfficeAssignment>() .Property(t => t.Timestamp) .IsRowVersion();
  • 表1对0..1(Instructor实体可以包含零个或一个OfficeAssignment)
    modelBuilder.Entity<OfficeAssignment>().HasRequired(t => t.Instructor).WithOptional(t => t.OfficeAssignment);
  • 表1对1
    modelBuilder.Entity<Instructor>().HasRequired(t => t.OfficeAssignment).WithRequiredPrincipal(t => t.Instructor);
  • 表1对n(Department为主表)
    modelBuilder.Entity<Staff>() .HasRequired(c => c.Department) .WithMany(t => t.Staffs)
  • 指定外键名(指定表Staff中的字段DepartmentID为外键)
    modelBuilder.Entity<Staff>() .HasRequired(c => c.Department) .WithMany(t => t.Staffs) .Map(m => m.MapKey("DepartmentID"));
  • 表n对n
    modelBuilder.Entity<Course>()
    .HasMany(t => t.Instructors)
    .WithMany(t => t.Courses)
  • 表n对n指定连接表名及列名
    modelBuilder.Entity<Course>()
    .HasMany(t => t.Instructors)
    .WithMany(t => t.Courses)
    .Map(m =>
    {
    m.ToTable("CourseInstructor");
    m.MapLeftKey("CourseID");
    m.MapRightKey("InstructorID");
    });



posted @ 2018-07-14 10:13 宣萱小童 阅读(...) 评论(...) 编辑 收藏