javax.persistence.NoResultException: getSingleResult() did not retrieve any entities

Question

i have created a namedquery with ejb to check if the username is used. When the singleResult is null, then i get the following Exception :

javax.persistence.         


        

Answer 1

try {
            Query queryObj = entityMgrObj
                    .createQuery("SELECT u FROM UserEntity u WHERE u.email = :email AND u.password = :password");
            queryObj.setParameter("email", email);
            queryObj.setParameter("password", password);
            UserEntity userEntity = (UserEntity) queryObj.getSingleResult();

            return userEntity;

        } catch (NoResultException e) {
            return null;
        }

Answer 2

Use getResultList instead and check if the List is empty (has zero element). Otherwise, the list contains one element and you simply return it.