@Query: How to Build complete SQL manually? (Spring JPA)

Question

I wan to build my sql statement manually with Java and then provide a final string to my repository like this:

public interface EventRepository extends CrudRepository<Event, Long>{

@Query("?1") 
List<Event> getLatestEventsFiltered(String sql); 
    
}

This doesn´t work because it is not according to syntax...it says : QuerySyntaxException: unexpected token: ?

But how to achive what I intent to do?

Thanks in advance!

Answer 1

You can't do that with @Query annotation.

First, we have to create a custom interface that declares our custom method:

public interface EventRepository extends CrudRepository<Event, Long> {
    List<Event> getLatestEventsFiltered(String sql);
}

public interface EventRepositoryCustom {
    List<Event> getLatestEventsFiltered(String sql);
}

Next, we'll provide our implementation of the EventRepository interface:

@Repository
public class EventRepositoryImpl implements EventRepositoryCustom {

    @PersistenceContext
    private EntityManager entityManager;

    @Override
    public List<Event> getLatestEventsFiltered(String sql) {
        Query query = entityManager.createNativeQuery(sql, Event.class);
        // You can use alternative query method instead of native query.
        List<Event> resultList = (List<Event>) query.getResultList();
        return resultList;
    }
}

Alternatively, another possibility that allows you to do pretty much anything is by using the Specification API. It allows you to create programmatically instead of a direct sql statement.