Question

我需要对以下SQL查询进行条件查询。

SELECT w.weight_id, w.weight, zc.charge
FROM weight w
LEFT OUTER JOIN zone_charge zc ON w.weight_id=zc.weight_id
AND zc.zone_id=?             <-------
ORDER BY w.weight ASC

相应的JPQL查询就像，

SELECT w.weightId, w.weight, zc.charge 
FROM Weight w 
LEFT JOIN w.zoneChargeSet zc 
WITH zc.zone.zoneId=:id      <-------
ORDER BY w.weight

我无法使用标准WITH zc.zone.zoneId=:id重现相同的内容。

以下条件查询使用where子句。

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Tuple>criteriaQuery=criteriaBuilder.createTupleQuery();
Root<Weight> root = criteriaQuery.from(entityManager.getMetamodel().entity(Weight.class));
SetJoin<Weight, ZoneCharge> join = root.join(Weight_.zoneChargeSet, JoinType.LEFT);

ParameterExpression<Long>parameterExpression=criteriaBuilder.parameter(Long.class);
criteriaQuery.where(criteriaBuilder.equal(join.get(ZoneCharge_.zoneTable).get(ZoneTable_.zoneId), parameterExpression));
criteriaQuery.multiselect(root.get(Weight_.weightId), root.get(Weight_.weight), join.get(ZoneCharge_.charge));
criteriaQuery.orderBy(criteriaBuilder.asc(root.get(Weight_.weight)));
TypedQuery<Tuple> typedQuery = entityManager.createQuery(criteriaQuery).setParameter(parameterExpression, 1L);
List<Tuple> list = typedQuery.getResultList();

如何修改它以使其对应...LEFT OUTER JOIN zone_charge zc ON w.weight_id=zc.weight_id AND zc.zone_id=?

这将生成以下SQL查询。

SELECT weight0_.weight_id  AS col_0_0_, 
       weight0_.weight     AS col_1_0_, 
       zonecharge1_.charge AS col_2_0_ 
FROM   social_networking.weight weight0_ 
       LEFT OUTER JOIN social_networking.zone_charge zonecharge1_ 
                    ON weight0_.weight_id = zonecharge1_.weight_id 
WHERE  zonecharge1_.zone_id =? 
ORDER  BY weight0_.weight ASC

Answer 1

with运算符是JPQL的特定于hibernate的扩展。您在标准API中找不到对它的支持。

Answer 2

这可以与JPA 2.1使用新功能join ON clause提供的条件API一起完成。因此，问题中给出的标准查询可以重写如下。

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Tuple>criteriaQuery=criteriaBuilder.createQuery(Tuple.class);
Root<Weight> root = criteriaQuery.from(entityManager.getMetamodel().entity(Weight.class));

ListJoin<Weight, ZoneCharge> join = root.join(Weight_.zoneChargeList, JoinType.LEFT);
criteriaQuery.multiselect(root.get(Weight_.weightId), root.get(Weight_.weight), join.get(ZoneCharge_.charge));

ParameterExpression<Long>parameterExpression=criteriaBuilder.parameter(Long.class);
join.on(criteriaBuilder.equal(join.get(ZoneCharge_.zoneTable).get(ZoneTable_.zoneId), parameterExpression));

criteriaQuery.orderBy(criteriaBuilder.asc(root.get(Weight_.weight)));
List<Tuple> list = entityManager.createQuery(criteriaQuery).setParameter(parameterExpression, 1L).getResultList();

它产生以下所需的SQL查询。

SELECT weight0_.weight_id  AS col_0_0_, 
       weight0_.weight     AS col_1_0_, 
       zonecharge1_.charge AS col_2_0_ 
FROM   social_networking.weight weight0_ 
       LEFT OUTER JOIN social_networking.zone_charge zonecharge1_ 
                    ON weight0_.weight_id = zonecharge1_.weight_id 
                       AND ( zonecharge1_.zone_id =? ) 
ORDER  BY weight0_.weight ASC

值得一提的是，此查询在Hibernate（4.3.5 final）上成功，但同样的查询在EclipseLink（2.5.1）上意外失败，但有以下异常。

java.lang.IllegalArgumentException: No parameter with name : Parameter[name=null] was found within the query: ReportQuery(referenceClass=Weight ).
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.setParameter(EJBQueryImpl.java:548)
    at admin.beans.ZoneChargeBean.getZoneChargeList(ZoneChargeBean.java:83)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
    at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
    at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4695)
    at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:630)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
    at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:46)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
    at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
    at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4667)
    at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4655)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    ... 72 more

必须删除

ParamterExpression才能使其按以下方式工作。

CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<Tuple>criteriaQuery=criteriaBuilder.createQuery(Tuple.class);
Root<Weight> root = criteriaQuery.from(entityManager.getMetamodel().entity(Weight.class));

ListJoin<Weight, ZoneCharge> join = root.join(Weight_.zoneChargeList, JoinType.LEFT);

criteriaQuery.multiselect(root.get(Weight_.weightId), root.get(Weight_.weight), join.get(ZoneCharge_.charge));
join.on(criteriaBuilder.equal(join.get(ZoneCharge_.zoneTable).get(ZoneTable_.zoneId), 1L));

criteriaQuery.orderBy(criteriaBuilder.asc(root.get(Weight_.weight)));
List<Tuple> list = entityManager.createQuery(criteriaQuery).getResultList();

它应该是EclipseLink 2.5.1的疏忽。

外部连接JPA中的ON条件

2 个答案: