Multiple JQPL fetch joins fail with Hibernate
Using Hibernate 3.6.7 and JPA 2, I cannot have two fetch joins in one query. Entity has a self referencing field called parent. localizedTexts is an @ElementCollection
, of Java type of Map. entity.getParent() has a @ManyToOne with EAGER loading strategy.
Here is How entity looks like:
@Entity
public class Entity extends BaseEntity {
/* ... */
@ManyToOne(fetch = FetchType.EAGER)
public Entity getParent() {
return parent;
}
@ElementCollection
@MapKeyColumn(name = "language")
@Column(name = "text")
public Map<String, String> getLocalizedTexts() {
return localizedTexts;
}
/* ... */
}
The following two queries work:
select开发者_C百科 e from Entity e join fetch e.parent.localizedTexts
select e from Entity e join fetch e.localizedTexts
But this doesn't work:
select e from Entity e join fetch e.localizedTexts join fetch e.parent.localizedTexts
Hibernate complains:
query specified join fetching, but the owner of the fetched association was not present in the select list [FromElement{explicit,collection join,fetch join,fetch non-lazy properties,classAlias=null,role=net.company.project.Entity.localizedTexts,tableName={none},tableAlias=localizedt3_,origin=null,columns={,className=null}}] [select e from net.company.project.Entity e join fetch e.localizedTexts join fetch e.parent.localizedTexts]
If you want to preload the Entities "parent" associations as well as the parent's "localizedTexts" association you should declare joins that traverse the model tree in the correct order:
select e from Entity e join fetch e.parent p joint fetch p.localizedTexts
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