HQL - EntityManager.createQuery 在 CaseInsensitiveComparator.compare 上抛出 NPE

问题描述

我正在尝试使用来自多个 SELECT 语句的列创建一个 SELECT 查询，但是它因 NPE 而失败。下面是查询，然后是堆栈跟踪。感谢您的帮助！

Query query = em.createquery("SELECT disTINCT " +
        "(SELECT count(*) AS totalPlayers FROM TeamEntity t,AssignmentsEntity a,JerseyEntity p " +
        "WHERE t.id = a.teamid AND p.jerseyId = a.jerseyid and t.id = :teamId)," +
        "(SELECT count(*) AS activePlayers FROM TeamEntity t2,AssignmentsEntity a2,JerseyEntity " +
        "WHERE t2.id = a2.teamid AND JerseyEntity.jerseyid = a2.jerseyid AND t2.id = :teamId " +
        "AND starttime > 0) " +
        "FROM TeamEntity");

query.setParameter("teamId",teamId);

java.lang.NullPointerException
    at java.lang.String$CaseInsensitiveComparator.compare(String.java:1192)
    at java.lang.String$CaseInsensitiveComparator.compare(String.java:1186)
    at java.util.TreeMap.getEntryUsingComparator(TreeMap.java:376)
    at java.util.TreeMap.getEntry(TreeMap.java:345)
    at java.util.TreeMap.get(TreeMap.java:278)
    at org.hibernate.dialect.function.sqlFunctionRegistry.findsqlFunction(sqlFunctionRegistry.java:45)
    at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.findsqlFunction(SessionFactoryHelper.java:385)
    at org.hibernate.hql.internal.ast.tree.IdentNode.getDataType(IdentNode.java:374)
    at org.hibernate.hql.internal.ast.HqlsqlWalker.lookupProperty(HqlsqlWalker.java:659)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.addrExpr(HqlsqlbaseWalker.java:5002)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.expr(HqlsqlbaseWalker.java:1286)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.exprOrSubquery(HqlsqlbaseWalker.java:4706)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.comparisonExpr(HqlsqlbaseWalker.java:4174)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.logicalExpr(HqlsqlbaseWalker.java:2138)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.logicalExpr(HqlsqlbaseWalker.java:2066)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.logicalExpr(HqlsqlbaseWalker.java:2063)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.logicalExpr(HqlsqlbaseWalker.java:2063)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.whereClause(HqlsqlbaseWalker.java:815)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.query(HqlsqlbaseWalker.java:609)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.selectExpr(HqlsqlbaseWalker.java:2466)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.selectExprList(HqlsqlbaseWalker.java:2232)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.selectClause(HqlsqlbaseWalker.java:1503)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.query(HqlsqlbaseWalker.java:585)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.selectStatement(HqlsqlbaseWalker.java:313)
    at org.hibernate.hql.internal.antlr.HqlsqlbaseWalker.statement(HqlsqlbaseWalker.java:261)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:271)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:191)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:143)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:119)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
    at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:153)
    at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:597)
    at org.hibernate.internal.AbstractSharedSessionContract.createquery(AbstractSharedSessionContract.java:706)
    at org.hibernate.internal.AbstractSharedSessionContract.createquery(AbstractSharedSessionContract.java:731)
    at org.hibernate.internal.AbstractSessionImpl.createquery(AbstractSessionImpl.java:23)

解决方法

不是我正在寻找的确切解决方案，但我只是使用了 em.createNativeQuery() 并且这对我有用。希望以后不会造成任何麻烦。

,

你试过了吗？

Query query = em.createQuery("SELECT DISTINCT " +
        "(SELECT count(*) AS totalPlayers FROM TeamEntity t,AssignmentsEntity a,JerseyEntity p " +
        "WHERE t.id = a.teamid AND p.jerseyId = a.jerseyid and t.id = :teamId)," +
        "(SELECT count(*) AS activePlayers FROM TeamEntity t2,AssignmentsEntity a2,JerseyEntity p " +
        "WHERE t2.id = a2.teamid AND p.jerseyid = a2.jerseyid AND t2.id = :teamId " +
        "AND starttime > 0) " +
        "FROM TeamEntity");