JPQL: boolean expression in CASE WHEN needs explicit comparison with TRUE/FALSE?

Question

I had tried the following:

SELECT NEW com.kawoolutions.bbstats.view.ScheduleGameLine(
    ga.id                                                                      AS gid
  , ga.scheduledTipoff                                                         AS scheduledtipoff
  ...
  , sch.finalScore                                                             AS homefinalscore
  , sca.finalScore                                                             AS awayfinalscore
  , CASE WHEN pah.wasWithdrawn OR paa.wasWithdrawn THEN TRUE ELSE FALSE END    AS waswithdrawn
  )

Last line is important. According to

JPQL/HQL and JPA/Hibernate: boolean expression in select constructor expression not working (unexpected AST node: AND, NPE, HqlSqlWalker.setAlias)?

the CASE WHEN is needed. However when running this, Hibernate fails with

Exception in thread "main" java.lang.IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: unexpected AST node: . near line 19, column 18
     at org.hibernate.hql.ast.QuerySyntaxException.convert(QuerySyntaxException.java:54)
     at org.hibernate.hql.ast.QuerySyntaxException.convert(QuerySyntaxException.java:47)
     at org.hibernate.hql.ast.ErrorCounter.throwQueryException(ErrorCounter.java:82)
     at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:261)
     at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185)
     at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
     at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
     at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
     at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:124)
     at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
     at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
     at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1770)
     at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:272)

It obviously isn't supported by JPA/Hibernate's grammar, but as Java and DB programmer I'd expect such expressions to work, like if ( hasHitHard ) ... and/or SELECT was_withdrawn...

Why has it been made this way or why isn't it supported as I expected?

Answer 1

Im not sure whether AS operator is supported by the select clause but in this case it is redundant anyway. As for the CASE operator maybe simple pah.wasWithdrawn OR paa.wasWithdrawn would be good enough:

SELECT NEW com.kawoolutions.bbstats.view.ScheduleGameLine(
     ga.id,ga.scheduledTipoff,...,
     sch.finalScore, sca.finalScore,
     pah.wasWithdrawn OR paa.wasWithdrawn
) from ...