问题
I'm trying to make a query using Spring Data, but I cannot make it work:
@Query(SELECT t FROM Thing t WHERE name LIKE :name AND CASE WHEN (:minVal <= 0) THEN TRUE ELSE (val <= :minVal) END AND CASE WHEN (:maxVal <= 0) THEN TRUE ELSE (val >= :maxVal) END)
Page<Thing> getThings(@Param("name") String name, @Param("maxVal") int maxVal, @Param("minVal") minVal);
StackTrace:
Caused by: java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected AST node: CASE near line 1, column 49 [SELECT t FROM Thing t WHERE name LIKE :name AND CASE WHEN (:minVal <= 0) THEN TRUE ELSE (val <= :minVal) END AND CASE WHEN (:maxVal <= 0) THEN TRUE ELSE (val >= :maxVal) END] at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1750) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1677) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1683) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:331) at sun.reflect.GeneratedMethodAccessor40.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:334) at com.sun.proxy.$Proxy83.createQuery(Unknown Source) at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:78) ... 207 more
Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected AST node: CASE near line 1, column 49 [SELECT t FROM Thing t WHERE name LIKE :name AND CASE WHEN (:minVal <= 0) THEN TRUE ELSE (val <= :minVal) END AND CASE WHEN (:maxVal <= 0) THEN TRUE ELSE (val >= :maxVal) END] at org.hibernate.hql.internal.ast.QuerySyntaxException.convert(QuerySyntaxException.java:91) at org.hibernate.hql.internal.ast.ErrorCounter.throwQueryException(ErrorCounter.java:109) at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:284) at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:206) at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:158) at org.hibernate.engine.query.spi.HQLQueryPlan.(HQLQueryPlan.java:126) at org.hibernate.engine.query.spi.HQLQueryPlan.(HQLQueryPlan.java:88) at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:190) at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:301) at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:236) at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1800) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:328)
I'm using this because I want to make a longer query using five filters at least, and I want to simplify the effort of doing the filter combinations making differents querys.
Don't know if there is a different (and better) way to do what I want, glad to ear it if it is.
Thank you.
EDIT: Using native query works fine, but isn't compatible with pagination yet...
回答1:
It looks like Hibernate cannot evaluate the result of a CASE expression when it returns a boolean literal directly. A workaround is to make the CASE expression part of another expression, e.g. by comparing it to another boolean literal.
So instead of:
... AND CASE WHEN (:minVal <= 0) THEN TRUE ELSE (val <= :minVal) END
Try:
... AND (CASE WHEN (:minVal <= 0) THEN TRUE ELSE (val <= :minVal) END) = TRUE
But looking at that expression, wouldn't it be simpler to just do:
... AND (:minVal <= 0 OR val <= :minVal)
Is it not equivalent?
来源：https://stackoverflow.com/questions/25710317/query-using-case-when-statement-in-where-causes-querysyntaxexception-unexpect