EF和NH关系对比之多对多(many to Many)

  public class Product
    {
        public int PID
        {
            get;
            set;
        }
        public string PName
        {
            get;
            set;
        }

        public virtual IList<Order> Orders
        {
            get;
            set;
        }
    }

    public class Order
    {
        public int OrderID
        {
            get;
            set;
        }

        public string OrderName
        {
            get;
            set;
        }

        public virtual IList<Product> Products
        {
            get;
            set;
        }
    }

 映射配置:

 public class ProductConfig:EntityTypeConfiguration<Product>
    {
        public ProductConfig()
        {
            this.HasKey(p => p.PID);
            this.Property(p => p.PName).HasMaxLength(255);
            this.HasMany(p => p.Orders)
                .WithMany(p => p.Products)
                .Map(map => {
                    map.MapLeftKey("ProductID");
                    map.MapRightKey("OrderID");
                    map.ToTable("Product_Order");
                });
        }
    }

    public class OrderConfig : EntityTypeConfiguration<Order>
    {
        public OrderConfig()
        {
            this.HasKey(p => p.OrderID);
            this.Property(p => p.OrderName).HasMaxLength(255);
        }
    }

 NH实体配置:

<class name="Product" table="T_Product">
        <id name="PID" column="[PID]">
            <generator class="native"/>
        </id>
        <property name="PName" column="PName" type="string" length="255"/>
        <bag name="Orders" table="Product_Order">
            <key column="ProductID"/>
            <many-to-many class="Order" column="OrderID"/>
        </bag>
    </class>

    <class name="Order" table="T_Order">
        <id name="OrderID" column="[OrderID]">
            <generator class="native"/>
        </id>
        <property name="OrderName" column="OrderName" type="string" length="255"/>
        <bag name="Products" table="Product_Order">
            <key column="OrderID"/>
            <many-to-many class="Product" column="ProductID"/>
        </bag>
    </class>

 EF的Many to Many 关系清晰明了！实在没有什么好说的！