Java HQL查询实现
我是Hibernate新手,我正在用Hibernate开发一个应用程序。具体来说,我尝试使用Hibernate实现以下SQL查询:Java HQL查询实现,java,hibernate,oracle11g,hql,Java,Hibernate,Oracle11g,Hql,我是Hibernate新手,我正在用Hibernate开发一个应用程序。具体来说,我尝试使用Hibernate实现以下SQL查询: select * from ifcitsv2013 where timestamp between startDate and finishDate and id = '50' 在Hibernate中,我有以下查询代码: DetachedCriteria dc = DetachedCriteria.forClass(IfcitsSensorphistory.cla
select * from ifcitsv2013 where timestamp between startDate and finishDate and id = '50'
在Hibernate中,我有以下查询代码:
DetachedCriteria dc = DetachedCriteria.forClass(IfcitsSensorphistory.class).add(Property.forName("id").eq(sDevice) );
List<Ifcitsv2013> readings = session.createCriteria(Ifcitsv2013.class).add(Property.forName("ifcitsSensorphistory").gt(dc)).list();
而类ifcitsensorphistory
是:
public class IfcitsSensorphistory {
private String id;
private String description;
private Timestamp starttime;
private Timestamp endtime;
private String timeseriesdatatype;
private String dataorigin;
private String usagedefineddataorigin;
private String unit;
private String value;
当我执行查询时,我得到了异常
:
Exception in thread "main" java.lang.NullPointerException
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getProjectedTypes(CriteriaQueryTranslator.java:362)
at org.hibernate.criterion.SubqueryExpression.createAndSetInnerQuery(SubqueryExpression.java:153)
at org.hibernate.criterion.SubqueryExpression.toSqlString(SubqueryExpression.java:69)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition(CriteriaQueryTranslator.java:380)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:114)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:83)
at org.hibernate.loader.criteria.CriteriaLoader.<init>(CriteriaLoader.java:92)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1687)
at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:347)
at com.cartif.dwhconnector.manager.DatabaseCommunicator.retrieveHistoricalData(DatabaseCommunicator.java:242)
at com.cartif.dwhconnector.manager.DWHManager.retrieveData(DWHManager.java:62)
at unittest.DWHConnectorTester.main(DWHConnectorTester.java:31)
线程“main”java.lang.NullPointerException中的异常
位于org.hibernate.loader.CriteriaQueryTranslator.getProjectedTypes(CriteriaQueryTranslator.java:362)
位于org.hibernate.criteria.SubqueryExpression.createAndSetInnerQuery(SubqueryExpression.java:153)
位于org.hibernate.criteria.SubqueryExpression.toSqlString(SubqueryExpression.java:69)
位于org.hibernate.loader.CriteriaQueryTranslator.getWhereCondition(CriteriaQueryTranslator.java:380)
位于org.hibernate.loader.criteria.CriteriaJoinWalker(CriteriaJoinWalker.java:114)
位于org.hibernate.loader.criteria.CriteriaJoinWalker(CriteriaJoinWalker.java:83)
位于org.hibernate.loader.criteria.CriteriaLoader.(CriteriaLoader.java:92)
位于org.hibernate.impl.SessionImpl.list(SessionImpl.java:1687)
位于org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:347)
位于com.cartif.dwhconnector.manager.DatabaseCommunicator.retrieveHistoricalData(DatabaseCommunicator.java:242)
位于com.cartif.dwhconnector.manager.DWHManager.retrieveData(DWHManager.java:62)
位于unittest.DWHConnectorTester.main(DWHConnectorTester.java:31)
有人能帮我开发正确的查询吗?确保您有一个打开的
会话
Query q = session.CreateQuery("select * from Ifcitsv2013 left join IfcitsSensorphistory as h where timestamp between :startDate and :finishDate and h.id = 50");
q.setDate("startDate", startDate);
q.setDate("finishDate", finishDate);
List result = q.list();
您好,感谢您的回复,我确信会话已打开,问题来自表Ifcitsv2013的id列之间的关系,它不是类中的直接属性,而是与表IFCITSSensorPhystorySure的关系。要从另一个表获得属性,您应该在查询中加入该表。
Query q = session.CreateQuery("select * from Ifcitsv2013 left join IfcitsSensorphistory as h where timestamp between :startDate and :finishDate and h.id = 50");
q.setDate("startDate", startDate);
q.setDate("finishDate", finishDate);
List result = q.list();