JPA/Hibernate Join On Constant Value

Question

I am trying to join to different entities from the same table using a constant value in the join statement. In SQL, I would do something like this...

SELECT         


        

Answer 1

If you don't mind using Hibernate-specific annotations you could try with the @WhereJoinTable annotation, e.g.:

@OneToOne(mappedBy = "owner", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinColumn(name = "ID", referencedColumnName = "ID")
@WhereJoinTable(clause = "TYPE = 'A'")
private TypeA inspectionSnapshot;

Note that the clause attribute must contain SQL, not JPQL, so you need to use the database column name instead of the JPA entity field name.