如何通过Spring Boot使用JPA的crudrepository执行存储过程？[PropertyReferenceException]

Question

I try to execute a postgres stored procedure which looks like that:

CREATE OR REPLACE FUNCTION get_subjects()
RETURNS SETOF subject AS
$$
SELECT * FROM subject;
$$
LANGUAGE 'sql';

I have a POJO class for subjects, a repository, and a service defined as follows:

@Entity
@Table(name = "subject")
@NamedStoredProcedureQueries({
        @NamedStoredProcedureQuery(name = "get_subjects",
                procedureName = "get_subjects")
})
public class Subject {

    @Id
    @Column(name = "uid")
    @Type(type = "pg-uuid")
    private UUID uid;
    private String name;
    private String start_date;
    private String end_date;

    protected Subject(){

    }

    public Subject(UUID uid, String name, String start_date, String end_date) {
        this.uid = uid;
        this.name = name;
        this.start_date = start_date;
        this.end_date = end_date;
    }

    //getter setter

@Repository
public interface SubjectRepository extends CrudRepository<Subject, Long> {

    @Procedure(name = "get_subjects")
    Collection<Subject> retrieveSubjects();
}


@Service
public class SubjectService {

    private final SubjectRepository subjectRepository;

    @Autowired
    public SubjectService(SubjectRepository subjectRepository) {
        this.subjectRepository = subjectRepository;
    }

    public Collection<Subject> getAllSubjects(){
        return subjectRepository.retrieveSubjects();
    }
}

The error caused by:

org.springframework.data.mapping.PropertyReferenceException: No property retrieveSubjects found for type Subject!

I tried to implement a SubjectRepositoryCustom, where I got a nullpointer back on Collection<Subject> . I went through some of the tutorials such as https://dzone.com/articles/calling-stored-procedures-from-spring-data-jpa . I also have a stored procedure running on one of my other repository where I insert with a stored procedure, which works excellent.

Could someone point out what cause the error and give a sample solution?

Answer 1

For your retrieveSubjects method you can use findAll() from CrudRepository. The get_subjects() procedure is not required in this simple case. See first example from https://docs.spring.io/spring-data/data-commons/docs/1.6.1.RELEASE/reference/html/repositories.html

For procedures I am using nativeQuery and let Spring to map the result correctly.

@Repository
public interface MyRepository extends CrudRepository<MyModel, Long> {

    @Query(value = "CALL my_procedure()", nativeQuery = true)
    List<MyModel> myProcedure();
}

If your procedure retrieves some computed/custom rows make sure that it retrieves an unique value for the @Id variable in each row. I had mapping issues using a wrong @Id column for a custom procedure result and ended using a temporary table with an unused primary key auto increment column.