EF data by adding navigation

Fluent Api is a correspondence between the model and the specified database table

// many 
the this .HasOptional (. X => X primary table) .WithMany (. X => x polyepitopic) .HasForeignKey (X => X polyepitopic primary table associated id.); 

// one 

 the this .HasRequired (X => X table 1.) .WithOptional (x => x table 2.);

 

 

 

Table has a primary key, foreign key no

Two entities following table

user table

public class User
{
    public User()
    {
        Orders =new HashSet<OrderInfo>()
    }

    public int Id{get;set;}
    public string Name{get;set;}

    public virtual ICollection<OrderInfo> Orders {get;set;}
}

Orders table

public class OrderInfo
    {
        public int Id { get; set; }
        public string OrderNo { get; set; }

        public string OrderName { get; set; }
        public virtual User User { get; set; }
    }

 

Specifies the correspondence between the user and the order by Fluent Api

 

 public class OrderInfo: EntityTypeConfiguration<OrderInfo>
    {
        public OrderInfo()
        {
            // Primary Key
            this.HasKey(t => t.Id);

          // Table & Column Mappings
            this.ToTable("OrderInfo");
           //添加导航属性
　　　　　　　　//

            this.HasOptional(x => x.User).WithMany(x => x.OrderInfo).HasForeignKey(x => x.Id);
        }
    }

 

Adding data will also save the user table and the Order table

User u=new User();

u.Name="张三";

OrderInfo orderInfo=new OrderInfo ();

u.Orders.Add(new OrderInfo(){ OrderNo="1234123"})

u.Orders.Add(new OrderInfo(){ OrderNo="12341221213"})

db.User.Add(u);

db.SaveChanges();