我有以下 map 。我希望将 BasketItem 映射到类“Product”。所以基本上,当我遍历购物篮时,我可以获得产品名称
<class name="BasketItem" table="User_Current_Basket">
<id name="Id" type="Int32" column="Id" unsaved-value="0">
<generator class="identity"/>
</id>
<property name="ProductId" column="Item_ID" type="Int32"/>
<one-to-one name="Product"
class="Product"></one-to-one>
</class>
如何指定该产品应将 BasketItem.ProductId 与 Product.Id 匹配
我还读到我应该避免一对一而只使用一对多?如果我要这样做,我如何确保我只得到一个产品而不是一个系列。
//编辑
select * from BasketItem
inner join Products on BasketItem.Item_ID = Products.Item_ID
请您参考如下方法:
How do specifiy that product should match BasketItem.ProductId with Product.Id
您的 BasketItem 应该包含对象级别的 Product,而不是 ProductId。映射应该是:
<class name="BasketItem" table="User_Current_Basket">
<id name="Id" type="Int32" column="Id" unsaved-value="0">
<generator class="identity"/>
</id>
<one-to-one name="Product" class="Product"/>
</class>
Also i've read that i should avoid one-to-one and just use one-to-many? If i was to do that how do i ensure i just get one product and not a collection.
如果您希望能够延迟加载 Product,请选择“假”多对一:
<class name="BasketItem" table="User_Current_Basket">
<id name="Id" type="Int32" column="Id" unsaved-value="0">
<generator class="identity"/>
</id>
<many-to-one name="Product" class="Product"/>
</class>
