Criteria subquery without projection fails throwing NullPointerException ------------------------------------------------------------------------ Key: HHH-993 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-993 Project: Hibernate Core Issue Type: Improvement Components: core Reporter: Johannes Rudolph Priority: Minor If you use a subquery in a criteria query and there is no projection, the execution of the query will fail by throwing a NullPointerException: Caused by: java.lang.NullPointerException at org.hibernate.loader.criteria.CriteriaQueryTranslator.getProjectedTypes(Crit eriaQueryTranslator.java:298) at org.hibernate.criterion.SubqueryExpression.toSqlString(SubqueryExpression.ja va:56) at org.hibernate.criterion.LogicalExpression.toSqlString(LogicalExpression.java :39) org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition(Crit eriaQueryTranslator.java:314) ... I think it is expected behaviour that restrictions only work on 1-dimensional return values of subqueries so it would be nice if Hibernate would mention that somewhere. It would be nice if you could just write: Criteria crit = dbSession.createCriteria(Bla.class); DetachedCriteria detachedCrit = DetachedCriteria.forClass(Blub.class).add( Restrictions.eq("condition", Boolean.FALSE)); crit.add( Restrictions.or( Restrictions.isNull("superBlub"), Subqueries.in("superBlub", detachedCrit ) ) ); since Hibernate entities could be seen as "entities" so Hibernate should automatically transform it into: DetachedCriteria detachedCrit = DetachedCriteria.forClass(Blub.class).add( Restrictions.eq("condition", Boolean.FALSE)) .setProjection( Projections.id() ); crit.add( Restrictions.or( Restrictions.isNull("superBlub"), Subqueries.propertyIn("ueberPartner", detachedCrit ) ) );