Spring Data JPA Querydsl不适用于投影

Question

@RequestMapping(value = "/testdsl", method = RequestMethod.GET)
 Iterable<User> index(
@QuerydslPredicate(root = User.class) Predicate predicate)
{
  return userRepository.findAll(predicate);
} 

public interface UserRepository extends CrudRepository<User, Integer>,
QueryDslPredicateExecutor<User>, QuerydslBinderCustomizer<QUser>
{
  //Collection<OnlyName> findAllProjectedBy();
  //OnlyName findProjectedById(Integer id);

@Override
default public void customize(QuerydslBindings bindings, QUser root)
{

    bindings.bind(String.class)
    .first((StringPath path, String value) ->    path.containsIgnoreCase(value));
 }
 }

public interface IUserProjection  {
 //...all required getters..
 }

Answer 1

你可以这样做，但你需要一个具体的课程...

class UserProjection {

  @QueryProjection
  public UserProjection(long id, String name){
     ...
  }

}

然后您的查询如下所示（在QueryDSL 3中）：

query.from(QTenant.tenant).list(new QUserProjection(QTenant.tenant.id, QTenant.tenant.name));

编辑：

List<UserProjection> dtos = query.select(new QUserProjection(QTenant.tenant.id, QTenant.tenant.name))
                              .from(tenant).fetch();