现在，我们来学习怎么使用Fluent API来配置实体。
一。配置默认的数据表Schema
Student实体
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace EF4
{
public class Student
{
public int StudentID { get; set; }
public string StudentName { get; set; }
public int StuaentAge { get; set; }
public string StudentEmail { get; set; }
public Standard Standard { get; set; }
}
}
Standard实体
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace EF4
{
public class Standard
{
public int StandardID { get; set; }
public int StandardName { get; set; }
public ICollection<Student> Students { get; set; }
}
}
上下文类：
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace EF4
{
public class DBContextClass:DbContext
{
public DBContextClass() : base("ConnectionStrings") { }
public DbSet<Student> Students { get; set; }
public DbSet<Standard> Standards { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.HasDefaultSchema("hello");
base.OnModelCreating(modelBuilder);
}
}
}
然后生成的数据表Schema就是我们配置的【hello】了
当然，你也可以分别对每个表，进行设置Schema。
二。把实体映射成表
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace EF4
{
public class DBContextClass:DbContext
{
public DBContextClass() : base("ConnectionStrings") { }
public DbSet<Student> Students { get; set; }
public DbSet<Standard> Standards { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//配置数据表的Schema
//modelBuilder.HasDefaultSchema("hello");
//将实体映射成表
modelBuilder.Entity<Student>().ToTable("WahHaHa");
modelBuilder.Entity<Standard>().ToTable("StandardInfo","xxx");
base.OnModelCreating(modelBuilder);
}
}
}
然后数据库是这样的：
打开表一个一个看：
三。将一个实体，拆分成多个表。
下面的代码是将Student实体拆分成两个表。
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace EF4
{
public class DBContextClass:DbContext
{
public DBContextClass() : base("ConnectionStrings") { }
public DbSet<Student> Students { get; set; }
public DbSet<Standard> Standards { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//配置数据表的Schema
//modelBuilder.HasDefaultSchema("hello");
//将实体映射成表
//modelBuilder.Entity<Student>().ToTable("WahHaHa");
//modelBuilder.Entity<Standard>().ToTable("StandardInfo","xxx");
//将一个实体映射成多个表
modelBuilder.Entity<Student>().Map(
m =>
{
m.Properties(p => p.StudentID);
m.Properties(p => p.StudentName);
m.ToTable("StudentInfo");
}).Map(
m =>
{
m.Properties(p => p.StudentID);
m.Properties(p => p.StuaentAge);
m.Properties(p => p.StudentEmail);
m.ToTable("StudentDetails");
});
modelBuilder.Entity<Standard>().ToTable("StandardInfo");
base.OnModelCreating(modelBuilder);
}
}
}
生成额数据库是：
上面的代码中，我们将Student实体，拆分成了两个表，StudentInfo和StudentDetail。
Map method need the delegate method as a parameter. You can pass Action delegate or lambda expression in Map method, as shown below.
Map方法需要委托作为参数。你可以传递一个Action委托或者lambda表达式在这个Map方法中。