| When you have inheritance hierarchy with "joined" inheritance type and query something from a subclass, superclass is always joined in the query even though it is not needed. Example: {{@Entity
@Inheritance(strategy = InheritanceType.JOINED)
public abstract class A { @Id @GeneratedValue private Long id; private String valA; // getters setters here } }} {{@Entity
public class SubA extends A { private String valSubA; // getters setters here } }} JPQL query:
select suba.valSubA from SubA suba Translated SQL query:
select suba0_.valSubA as col_0_0_ from SubA suba0_ inner join A suba0_1_ on suba0_.id=suba0_1_.id Super class table join is useless in the SQL query. It could be optimized. I discussed that on Hibernate forum |
