[英]HQL equivalent query to criteria query in hibernate many to many relationship?
我有两个表库存和类别,它们之间具有多对多关系。
Stock.hbm.xml
<hibernate-mapping>
<class name="hibernate.mapping.manytomany.Stock" table="stock">
<id name="stockId" type="java.lang.Integer">
<column name="STOCK_ID" />
<generator class="identity" />
</id>
<property name="stockCode" type="string">
<column name="STOCK_CODE" length="10" not-null="true" unique="true" />
</property>
<property name="stockName" type="string">
<column name="STOCK_NAME" length="20" not-null="true" unique="true" />
</property>
<set name="categories" table="stock_category"
inverse="false" lazy="true" fetch="select" cascade="all" >
<key>
<column name="STOCK_ID" not-null="true" />
</key>
<many-to-many entity-name="hibernate.mapping.manytomany.Category">
<column name="CATEGORY_ID" not-null="true" />
</many-to-many>
</set>
</class>
</hibernate-mapping>
Category.hbm.xml
<hibernate-mapping>
<class name="hibernate.mapping.manytomany.Category" table="category">
<id name="categoryId" type="java.lang.Integer">
<column name="CATEGORY_ID" />
<generator class="identity" />
</id>
<property name="name" type="string">
<column name="NAME" length="10" not-null="true" />
</property>
<property name="desc" type="string">
<column name="[DESC]" not-null="true" />
</property>
<set name="stocks" table="stock_category" inverse="true" lazy="true"
fetch="select">
<key>
<column name="CATEGORY_ID" not-null="true" />
</key>
<many-to-many entity-name="hibernate.mapping.manytomany.Stock">
<column name="STOCK_ID" not-null="true" />
</many-to-many>
</set>
</class>
</hibernate-mapping>
这是我的条件查询,
Criteria c = session.createCriteria(Category.class, "c");
c.createAlias("c.stocks", "s");
c.add(Restrictions.eq("c.categoryId", 1));
c.setProjection(Projections.projectionList()
.add(Projections.property("s.stockId"))
.add(Projections.property("s.stockName")));
在这种情况下,我需要等效的HQL。我已经尝试过了,但结果却不同
String query = "select c.stocks.stockId, c.stocks.stockName from Category c where
c.categoryId=1"
让我知道您是否需要更多详细信息。
好的,显然,您错过了文档中有关连接的部分:
select s.stockId, // equivalent to the s.stockId projection
s.stockName // equivalent to the s.stockName projection
from Category c // equivalent to the root criteria creation
join c.stocks s // equivalent to the alias creation
where c.categoryId = 1 // equivalent to the restriction addition
我打算彻底调查此问题。 我现在从以前的答案中怀疑的是,join语句中应该有ON子句 。 如果我的期望不对,请原谅我。
select s.stockId,s.stockName from Category c join c.stocks s
on c.stockId=s.stockId where c.categoryId = 1 ;
//it might be on c.CATEGORY_ID=s.CATEGORY_ID also
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