CODEWITHSUNDEEP
jakarta-eejpajpql
Clawdidr
Clawdidr

Reputation: 616

Subclass discrimination (TYPE) using a class member in JPA/JPQL

I want to discriminate by type in a query, but what I want to discriminate is not the entity in the SELECT clause, but a member of it.

For example, instead of using TYPE like this:

SELECT p
FROM Project p
WHERE TYPE(p) = DesignProject OR TYPE(p) = QualityProject

I need to use it like this:

SELECT p
FROM Project p
WHERE TYPE(p.leader) = Architect OR TYPE(p.leader) = Engineer

Architect and Engineer are subclasses of Leader class.

I have already tried that, but I am getting this error:

org.hibernate.QueryException: could not resolve property

Upvotes: 1

Views: 1234

Answers (1)

Koitoer
Koitoer

Reputation: 19543

Try this. 

   SELECT d
    FROM Project p join p.leader d
    WHERE TYPE(d) = Architect OR TYPE(d) = Engineer

Upvotes: 3

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