JPA/Hibernate query with class name?
- by Petteri Hietavirta
In this example com.test.Cat extends com.test.Animal and there is no field DB in CAT table of com.test.Cat explicitly defining its type (it wasn't me).
When I query my animals from DB I get a collection of Animals.
It is possible to sort them by class name:
order by r.class
but is there a way to use class name as a criteria? For example I would like to get all animals expect dogs. But no luck - even this does not work:
where r.class = ? (String "ccc.test.Cat")
as I get an exception:
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer
at org.hibernate.type.IntegerType.set(IntegerType.java:64)
at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:154)
at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:136)
at org.hibernate.param.PositionalParameterSpecification.bind(PositionalParameterSpecification.java:62)
at org.hibernate.loader.hql.QueryLoader.bindParameterValues(QueryLoader.java:514)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1589)
at org.hibernate.loader.Loader.doQuery(Loader.java:696)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
at org.hibernate.loader.Loader.doList(Loader.java:2228)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
at org.hibernate.loader.Loader.list(Loader.java:2120)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:361)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1148)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:67)
