org.hibernate.QueryException: query specified join fetching, but the owner of the fetched association was not present in the sel
错误日志:
2009-8-20 12:17:56 org.zkoss.zk.ui.impl.UiEngineImpl handleError:1108 严重: >>java.lang.IllegalArgumentException: org.hibernate.QueryException: query specified join fetching, but the owner of the fetched association was not present in the select list [FromElement{explicit,not a collection join,fetch join,fetch non-lazy properties,classAlias=null,role=null,tableName=SGVD.TPROFILE,tableAlias=tprofile1_,origin=SGVD.TPROFILEPERSON tprofilepe0_,colums={tprofilepe0_.PROFILEID ,className=mo.org.sgvd.domain.Tprofile}}] [SELECT pfp.tprofile FROM mo.org.sgvd.domain.Tprofileperson pfp left join fetch pfp.tprofile WHERE pfp.tperson.personid = 114] >>org.hibernate.QueryException: query specified join fetching, but the owner of the fetched association was not present in the select list [FromElement{explicit,not a collection join,fetch join,fetch non-lazy properties,classAlias=null,role=null,tableName=SGVD.TPROFILE,tableAlias=tprofile1_,origin=SGVD.TPROFILEPERSON tprofilepe0_,colums={tprofilepe0_.PROFILEID ,className=mo.org.sgvd.domain.Tprofile}}] [SELECT pfp.tprofile FROM mo.org.sgvd.domain.Tprofileperson pfp left join fetch pfp.tprofile WHERE pfp.tperson.personid = 114] >> at org.hibernate.hql.ast.tree.SelectClause.initializeExplicitSelectClause(SelectClause.java:195) >> at org.hibernate.hql.ast.HqlSqlWalker.useSelectClause(HqlSqlWalker.java:705) >> at org.hibernate.hql.ast.HqlSqlWalker.processQuery(HqlSqlWalker.java:529) >> at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:645) >> at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:281) >>...
错误原因分析:
首先看HQL语句:
SELECT pfp.tprofile FROM Tprofileperson pfp left join fetch pfp.tprofile WHERE pfp.tperson.personid = 114
此处我希望加载Tprofileperson下的tprofile,而我使用了fetch来立即抓取tprofile,错误就在这里.如果你使用fetch,那么fetch左边的连接对象(拥有者)一定要出现在select后,例如将上面改为select pfp... 这样就会执行正常,因为使用了fetch,Hibernate就会将需要fetch的对象(Tprofile)立即加载在父对象(Tprofileperson)中,而我的select确只是列出子对象,而拥有者(Tprofileperson)并没有present(出席在结果集中),那么就会出现以上错误.
下面我们看另外会出现同样错误的语句:
01: select person from Person as person 02: left join person.address as address 03: left join fetch address.country as country
你可以看到在第3行使用了fetch,而第2行确没有使用fetch,那么第3行fetch的拥有者address并没有立即被抓取,这就会导致同样的错误,将第2行中的join后加上fetch,即可解决问题.
总结:
如果使用了fetch,那么拥有者一定要present,也就是对象一定要被加载出来
参考资料:
http://lamnguyenblog.com/2008/10/common-hibernate-errors-and-causes/
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