hibernate - 集合中的 HQL 排序依据

Question

我有 2 个实体：汽车和车轮（oneToMany），我想取回我的汽车，所有的车轮和（这是棘手的部分）由 wheel.location 排序。下面的代码引发异常，并显示消息“非法尝试取消引用集合”。

Select c
  from Car
       LEFT JOIN FETCH c.wheels
order by c.wheels.location

任何想法如何做到这一点，如果这在 HQL 中是可能的？

Answer 1

SELECT DISTINCT c
  FROM Car
       LEFT JOIN FETCH c.wheels AS wheels
ORDER BY wheels.location

Answer 2

唔。认为您可能需要使用别名？

Select c from Car
       LEFT JOIN FETCH c.wheels wheel
order by wheel.location

Answer 3

我认为您必须在 from 请求中设置 Car 别名：

SELECT DISTINCT c
  FROM Car c
       LEFT JOIN FETCH c.wheels AS wheels
ORDER BY wheels.location

以下是有关hql 订购的 Hibernate 文档的摘录：

select cat from Cat cat
       join cat.kittens kitten
group by cat.id, cat.name, cat.other, cat.properties
having avg(kitten.weight) > 100
order by count(kitten) asc, sum(kitten.weight) desc