Question

我尝试实现多个分离查询以获取userId。但是它会抛出空指针异常。我尝试了很多解决方案，但是我没有得到正确的输出。

DetachedCriteria getShortListUser = DetachedCriteria
    .forClass(ShortListedProfileVO.class,"ug")
    .setProjection(Property.forName("ug.candidateId"))
    .add(Restrictions.eq("ug.employerId.parentUserId",employerIdParentId));

DetachedCriteria exampleSubquery = DetachedCriteria
    .forClass(PreferedLocationsVO.class,"pg")
    .setProjection(Property.forName("pg.userId"))   
    .add(Restrictions.in("pg.cityId.id",preferredLocations))
    .add(Property.forName("pg.userId").notIn(getShortListUser));

此处我附上了例外

显示java.lang.NullPointerException 在org.hibernate.criterion.SubqueryExpression.getTypedValues（SubqueryExpression.java:80）在org.hibernate.loader.criteria.CriteriaQueryTranslator.getQueryParameters（CriteriaQueryTranslator.java:251）在org.hibernate.criterion.SubqueryExpression.toSqlString（SubqueryExpression.java:55）在org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition（CriteriaQueryTranslator.java:334）在org.hibernate.loader.criteria.CriteriaJoinWalker。（CriteriaJoinWalker.java:71）在org.hibernate.loader.criteria.CriteriaLoader。（CriteriaLoader.java:68）在org.hibernate.impl.SessionImpl.list（SessionImpl.java:1550）在org.hibernate.impl.CriteriaImpl.list（CriteriaImpl.java:283）在com.loginhire.employer.dao.EmployerSearchEmployeeDAO.SearchEmployee（EmployerSearchEmployeeDAO.java:79）在com.loginhire.employer.action.VacancyAction.search（VacancyAction.java:612） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57） at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:601）在com.opensymphony.xwork2.DefaultActionInvocation.invokeAction（DefaultActionInvocation.java:453）在com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly（DefaultActionInvocation.java:292）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:255）在org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept（DebuggingInterceptor.java:256）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:249） at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept（DefaultWorkflowInterceptor.java:176） at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept（MethodFilterInterceptor.java:98）在com.opensymphony.xwork2.DefaultActionInvocation.invoke（DefaultActionInvocation.java:249）

Answer 1

如果没有完整的（或至少相关的）映射（带注释的实体），很难判断。但至少有两个可疑部分。

在限制中链接的属性是＆＃34; ug.employerId.parentUserId＆＃34;

...
.add(Restrictions.eq("ug.employerId.parentUserId",employerIdParentId));

老实说，我希望你的模型是＆＃34; ug.employer.parentUser.Id＆＃34;

...
.add(Restrictions.eq("ug.employer.parentUser.Id",employerIdParentId));

此外，要求employer表示我们需要加入 employer table 。这不是隐含的，所以像：

DetachedCriteria getShortListUser = DetachedCriteria
.forClass(ShortListedProfileVO.class,"ug")
.createCriteria("ug.employer", "employer") // JOIN THE employer
// or alias
.createAlias("ug.employer", "employer") // JOIN THE employer
...

选中此hibernate - createCriteria or createAlias?

还可以尝试使用这些部分来获取文档（与Hiberante 3相关）

Answer 2

您将创建多个分离标准，并应附加会话条件。

DetachedCriteria getShortListUser = DetachedCriteria
    .forClass(ShortListedProfileVO.class,"ug")
    .setProjection(Property.forName("ug.candidateId"))
    .add(Restrictions.eq("ug.employerId.parentUserId",employerIdParentId));

Criteria criteria = getSession().createCriteria(PreferedLocationsVO.class)
    .setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
    .add(Restrictions.or(
        Subqueries.propertyIn("userId", getShortListUser)));

如果您有多个子查询，

Criteria criteria = getSession().createCriteria(PreferedLocationsVO.class)
    .setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
    .add(Restrictions.or(
        Subqueries.propertyIn("userId", getShortListUser),
        Subqueries.propertyIn("employeeId", anotherDetachedCriteria)));

More Example

Hibernate Criteria多个分离查询的分离查询空指针问题

2 个答案: