CrazyJPARequirements

andries.sp · **Joined:** Tue Nov 21, 2006 8:59 am **Posts:** 1

I have this really crazy problem with the JPA Query Language. The basic structure on the database is as follows:

Code:

   Vehicle --(1-to-many)--> 
           RatePeriod --(1-to-many) --> 
               RateValue  

RateValue has a field called "minDays" which determines the first rate value applicable for a specific duration (eg 12 days, 14 days, 31 days, 99 days ), the idea is to select the max value available, (for example if days==16 then minDays should be 14, etc.. ). At the moment I use a sub-query to restrict the values for a specific period.

Query (1) works fine, but the moment I add the sub query to restrict the values per period on query (2) I get this huge completely insane stack trace. (See stack trace). I spend a whole day going through the JPA specification, and the hibernate documents. I still cannot see what is wrong the query statement. I strongly believe that a "NullPointerExcption" inherently indicates a problem in the Hibernate library.

These exceptions only started after I upgraded from 3.2.0.cr4 to 3.2.0.GA.

Query-1

Code:

SELECT 
    v.period.vehicle,
    v.period.rate,
    max(v.value)
FROM 
    RateValue AS v
WHERE 
    v.period.startDate        <= :startDate
    AND v.period.endDate           > :startDate
    AND v.period.rate.code         = :rateCode
    AND v.period.account.id        = :accountId
    AND v.period.loyaltyProgram    = :isLoyaltyProgram
GROUP BY 
    v.period.vehicle,
    v.period.rate

Query-2

Code:

SELECT 
    v.period.vehicle,
    v.period.rate,
    max(v.value)
FROM 
    RateValue AS v
WHERE 
    v.minDays = ( select max( t.minDays ) from RateValue as t where t.period = v.period AND t.minDays <= :days )
    AND v.period.startDate        <= :startDate
    AND v.period.endDate           > :startDate
    AND v.period.rate.code         = :rateCode
    AND v.period.account.id        = :accountId
    AND v.period.loyaltyProgram    = :isLoyaltyProgram
GROUP BY 
    v.period.vehicle,
    v.period.rate

Stack trace

Code:

Exception in thread "main" java.lang.NullPointerException
   at org.hibernate.hql.ast.tree.FromClause.findIntendedAliasedFromElementBasedOnCrazyJPARequirements(FromClause.java:120)
   at org.hibernate.hql.ast.tree.FromClause.getFromElement(FromClause.java:107)
   at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:81)
   at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:70)
   at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:265)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3056)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:2945)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:688)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:544)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.collectionFunctionOrSubselect(HqlSqlBaseWalker.java:4253)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.inRhs(HqlSqlBaseWalker.java:4161)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.comparisonExpr(HqlSqlBaseWalker.java:3842)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.logicalExpr(HqlSqlBaseWalker.java:1762)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.logicalExpr(HqlSqlBaseWalker.java:1690)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.whereClause(HqlSqlBaseWalker.java:776)
   at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:577)
   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:112)
   at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1623)
   at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:92)

andydale · **Posted:** Thu Nov 23, 2006 3:54 am

Hi,

I also had this, and submitted a JIRA issue for it http://opensource.atlassian.com/projects/hibernate/browse/HHH-2159 basically you will have to modify the source code if you want to get it working with 3.2.0GA, but i spoke with Max at JBoss world and he recommended upgrading to version 3.2.1GA.

I plan test 3.2.1 later on today.

Cheers,

Andy

andydale · **Posted:** Thu Nov 23, 2006 5:31 am

The bug still exists in 3.2.1GA, so if you want to use a GA release you will have to modify the source code (very minor modification) to stop null values being added to the map in the first place.

Cheers,

Andy