Spring Data JPA custom repository query not returning anything

Question

public class Foo{
   private String foo;
   private String bar;
   //class methods
}

public List<Foo> findByFooBarContains(@Param("bar")String bar) {
   TypedQuery<Foo> query = entityManager.createQuery("SELECT foo FROM Foo foo WHERE foo.bar LIKE '%:bar%'", Foo.class);
   return query.getResultList();
}

I've tested with JPA standard findByName contains and it is working as it should. However my custom query is returning nothing. what am I doing wrong?

Answer 1

Assuming that you have a JPA repository interface, you can simply define a query method like:

public interface FooRepo extends JpaRepository<FooRepo, String>{
  
  //Query Method
  List<Foo> findByBarContains(String bar);

}

You can then call this method from your Service like:

@Service
public class FooService {

    @Autowired
    private FooRepo fooRepo;

    public List<Foo> fetchByBarContains(String bar){
        return fooRepo.findByBarContains(bar);
    }

}

You can also implement native or JPQL queries by defining them in your Repository like:

//JPQL (foo here is your model and not the table)
@Query("SELECT foo FROM Foo WHERE bar LIKE %?1%")
List<Foo>findByBarContains(String bar);

//Native
@Query(
  value = "SELECT foo FROM Foo WHERE bar LIKE %?1%", 
  nativeQuery = true)
  List<Foo>findByBarContains(String bar);

Of course, your model should be Annotated with @Entity like:

@Entity(name="Foo")
public class Foo{
    
   @Id
   private String foo;
   
   //Use @Column annotation if your database column has a different name than your field
   @Column(name = "BAR")
   private String bar;
    // getters and setters
    
}

On the other hand, if you want to use entity manager, you can do:

public List<Foo> findByFooBarContains(String bar) {
return entityManager.createQuery(
    "SELECT foo FROM Foo foo WHERE foo.bar LIKE %:bar%", Foo.class)
    .setParameter("bar", bar)
    .getResultList();
}

I think the ".setParameter("bar", bar)" is what you're missing in your code.