JPA Criteria API: Multiple condition on LEFT JOIN

Question

I have a join reference like following for which the first join expression is constructed by the JPA API automatically.

CriteriaBuilder cb = entityManager.ge         


        

Answer 1

JPA always joins by the mapping join columns, only. JPA 2.0 does not support an ON clause, but the 2.1 draft does have this support.

EclipseLink 2.4 has support for an ON clause,

See, http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic_JPA_Development/Querying/JPQL#ON

It is also possible through the Criteria API, using the EclipseLink native Expression API that provides on clause support,

See, http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic_JPA_Development/Querying/Criteria#JpaCriteriaBuilder_and_EclipseLink_Extensions