Spring Data JPA, hibernate: update all query and SET value by selecting from another table

Question

Is the following SQL possible in a JPA query? I tried but the actual SQL hibernate runs doesn't seem right.

This is the SQL i want to write as JPA query;

UPDATE movie m SET average_rating = COALESCE((SELECT AVG(stars) FROM rating r WHERE r.movie_id = m.id), 0);

This is the JPA query;

@Query("UPDATE Movie m SET m.averageRating = COALESCE((SELECT AVG(r.stars) FROM Rating r WHERE r.movie = m), 0)")

And what hibernate says;

Hibernate:
    insert
    into
        HT_Movie
        select
            movie0_.id as id
        from
            Movie movie0_
Hibernate:
    update
        Movie
    set
        average_rating=coalesce((select
            avg(rating1_.stars)
        from
            Rating rating1_
        where
            rating1_.movie_id=id),
        0)
    where
        (
            id
        ) IN (
            select
                id
            from
                HT_Movie
        )

so there seems to be an additional where being added by hibernate.

Answer 1

@Query("UPDATE Movie m SET m.averageRating = COALESCE((SELECT AVG(r.stars) FROM Rating r WHERE r.movie = m), 0)")

This is 100% correct. And hibernate works correctly as well. Hibernate works in this way:

1. Create a temporary table HT_Movie and insert the ids of Movie table.
2. Create the JPA query as a whole where
3. Compare abstracting ids from HT_Movie t enforce more speed in update processing

And this is not new hibernate always fabricates queries.