`Type cannot be null` exception when trying to run out Stored Procedure using Spring Data JPA

Question

I am trying to invoke a Stored Procedure whose signature looks like the following:

CREATE OR REPLACE PROCEDURE FIND_FIRST_BOOKMARK_GT(bookmark IN NUMBER, cur OUT         


        

Answer 1

This is an old question, but I faced with same issue and get fixed finally after a couple of hours of "read docs-try-error". Maybe this could be useful to someone. Your repository must look like this:

@Repository
public interface ResponseRepository extends CrudRepository<Response, Long>{
    @Procedure(name = "Response.findFirstBookmarkGreaterThan")
    Response findFirstBookmarkGreaterThan(@Param("bookmark") Long bookmark);
}

The key is at @Procedure annotation. Use "name" instead of "value" (by default) when coding this annotation. This article at Baeldung blog gave me the final pull to resolve this error: https://www.baeldung.com/spring-data-jpa-stored-procedures.

Answer 2

Faced with the same issue using @Procedure. As a workaround, you could refer to the entityManager in the service class and call procedure from it.

@Service
public interface ResponseService {

    @PersistenceContext
    EntityManager entityManager;

    public Response findFirstBookmarkGreaterThan(Long bookmark){
          Query query  = entityManager.createNamedStoredProcedureQuery("Response.findFirstBookmarkGreaterThan");
          query.setParameter("bookmark", bookmark);
          return query.getFirstResult();
    };
}

Note that Response must be an @Entity.

Answer 3

Using native Query we can also call store procedure. If you are using MySQL then following will be the systex:

 @Query(nativeQuery = true,value = "call getEmployeeList")
 List<Employee> getEmployeeList();

Answer 4

I was not able to get this syntax working as such, however, the notion of retrieving from a stored procedure is effectively a shorthand for selecting from (possibly a view) mixed with applying some input based function. To that effect, I have replaced my stored procedure with a function / table that yields the same effect.

@Query("SELECT r FROM RESPONSES r WHERE BOOKMARK = FIND_FIRST_BOOKMARK_GT(:bookmark)")
Response findFirstBookmarkGreaterThan(@Param("bookmark") Long bookmark);

This uses the @Query syntax in conjunction with a table and a function, whose overall logic is identical to calling the stored procedure I had intended. Although a little more difficult to follow perhaps, the syntax is at least much shorter than using the @NamedStoredProcedureQuery.

The function does the same thing the stored procedure originally did EXCEPT for the last part which was a SELECT INTO, this is now encapsulated as part of the @Query.