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我正在自定义N2CMS的数据库结构,并遇到了一个问题。下面列出了这两个类。Nhibernate一对多每个子类都有表
public class Customer : ContentItem
{
public IList<License> Licenses { get; set; }
}
public class License : ContentItem
{
public Customer Customer { get; set; }
}
nhibernate映射如下。
<class name="N2.ContentItem,N2" table="n2item">
<cache usage="read-write" />
<id name="ID" column="ID" type="Int32" unsaved-value="0" access="property">
<generator class="native" />
</id>
<discriminator column="Type" type="String" />
</class>
<subclass name="My.Customer,My" extends="N2.ContentItem,N2" discriminator-value="Customer">
<join table="Customer">
<key column="ItemID" />
<bag name="Licenses" generic="true" inverse="true">
<key column="CustomerID" />
<one-to-many class="My.License,My"/>
</bag>
</join>
</subclass>
<subclass name="My.License,My" extends="N2.ContentItem,N2" discriminator-value="License">
<join table="License" fetch="select">
<key column="ItemID" />
<many-to-one name="Customer" column="CustomerID" class="My.Customer,My" not-null="false" />
</join>
</subclass>
然后,当得到客户的情况下,customer.Licenses永远是空的,但实际上是在数据库中为客户许可证。当我检查了NHibernate的日志文件,我发现SQL查询是这样的:
SELECT licenses0_.CustomerID as CustomerID1_,
licenses0_.ID as ID1_,
licenses0_.ID as ID2_0_,
licenses0_1_.CustomerID as CustomerID7_0_,
FROM n2item licenses0_
inner join License licenses0_1_
on licenses0_.ID = licenses0_1_.ItemID
WHERE licenses0_.CustomerID = 12 /* @p0 */
看来,NHibernate的认为,在客户是在“n2item”表。我不知道为什么,但为了使它工作,我认为SQL应该是这样的。
SELECT licenses0_.ID as ID1_,
licenses0_.ID as ID2_0_,
licenses0_1_.CustomerID as CustomerID7_0_,
FROM n2item licenses0_
inner join License licenses0_1_
on licenses0_.ID = licenses0_1_.ItemID
WHERE licenses0_1_.CustomerID = 12 /* @p0 */
难道有人指出我的映射有什么问题吗?我怎样才能获得一个客户的正确许可?提前致谢。
感谢梅森,我想我应该坚持使用内置的n2数据库结构,因为定制的有很多问题。 – wenqiang 2010-04-12 09:41:29
子类映射没有问题我添加了一对多元素。而且我已经尝试了一对多和包包元素上的几乎所有属性。没有用。 – wenqiang 2010-04-12 09:42:58