[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-2978) Using HQL index() on a <index-many-to-many..> key in a <map...> cannot dereference any properties of the key - java.lang.NullPointerException

Using HQL index() on a <index-many-to-many..> key in a <map...> cannot dereference any properties of the key - java.lang.NullPointerException --------------------------------------------------------------------------------------------------------------------------------------------- Key: HHH-2978 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-2978 Project: Hibernate3 Issue Type: Bug Components: query-hql Affects Versions: 3.2.5 Environment: Hibernate 3.2.5 GA, MySQL 5.0.27 Community NT, Eclipse 3.1.1, Hibernate Tools 3.2 beta 9 Reporter: James Andrews As mentioned in summary, using a mapped POJO as the index of a <map..> relationship, via the <index-many-to-many class="..> approach. Using a table join, for instance: select index(depts), depts from ModificationFixed fixed left join fixed.departments depts Will fetch Department instances for each value, but if you instead try to fetch a property of the index: select index(depts).name, depts from ModificationFixed fixed left join fixed.departments depts then this causes the aforementioned NullPointerException, both in the hibernate tools preview, and in practise when trying to execute the query, with the following stack trace: Exception in thread "main" java.lang.NullPointerException at org.hibernate.hql.ast.HqlSqlWalker.lookupProperty(HqlSqlWalker.java:444) at org.hibernate.hql.antlr.HqlSqlBaseWalker.propertyRef(HqlSqlBaseWalker.java:1080) at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectExpr(HqlSqlBaseWalker.java:1881) at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectExprList(HqlSqlBaseWalker.java:1825) at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectClause(HqlSqlBaseWalker.java:1394) at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:553) at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:281) at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:229) at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:228) at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:160) at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:111) at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:77) at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:56) at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:72) at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:133) at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:115) at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1623) at intranet.db.PersistentMySQL.createQueryArray(PersistentMySQL.java:154) at intranet.budget.planner.ModificationFixed.main(ModificationFixed.java:165)