Multiple aliases with QuerydslBinderCustomizer

Question

I'm using QuerydslPredicate in my RestController on an entity which has a date object, I want to be able to query for a date before/after/between given dates, hoping to have something like

• GET /problems?createdOnAfter=XXX
• GET /problems?createdOnBefore=YYY
• GET /problems?createdOnAfter=XXX&createdOnBefore=YYY

My entity has the date field createdOn and I was hoping I could customise bindings for an entity path using multiple aliases i.e. adding aliases createdOnAfter & createdOnBefore - it doesn't look like I can create multiple aliases though, e.g.

@Repository
public interface ProblemRepository extends JpaRepository<Problem, String>, QueryDslPredicateExecutor<Problem>,
        QuerydslBinderCustomizer<QProblem> {

            ....

    @Override
    default void customize(QuerydslBindings bindings, QProblem root) {
        bindings.bind(root.createdOn).as("createdOnAfter").first(TemporalExpression::after);
        bindings.bind(root.createdOn).as("createdOnBefore").first(TemporalExpression::before);
    }
}

The before alias is obviously overwriting the after one.

What's the correct approach to avoid having to manually create the predicates?

Answer 1

Why not using QueryDSL Predicate ? You could do :

@GetMapping("/problems")
@Timed
public ResponseEntity<List<ProblemDTO>> getAllProblems(
      @RequestParam(required = false) LocalDateTime createdOnAfter, 
      @RequestParam(required = false) LocalDateTime createdOnBefore,
      @ApiParam Pageable pageable) {
    BooleanBuilder where = new BooleanBuilder();
    if (startDate != null) {
        where = where.and(problem.createdOn.after(createdOnAfter));
    }
    if (endDate != null) {
        where = where.and(problem.createdOn.before(createdOnBefore));
    }
    Page<Donnee> page = problemRepository.findAll(where, pageable);
    return new ResponseEntity<>(problemMapper.toDTO(page.getContent())), null, HttpStatus.OK);
}

Hope it helps, Regards