Question

我有一个hql请求，如下所示：

select Distinct prof 
from Professor as prof 
left join fetch prof.students as stud

教授和学生处于多种关系中。我想按学生的名字订购教师名单。

我试过了：

select Distinct prof
from Professor as prof
left join fetch prof.students as stud
order by prof.students.name

我收到了错误：严重：org.springframework.orm.hibernate3.HibernateQueryException：非法尝试解除引用集合

我也尝试过：

select Distinct prof
from Professor as prof
left join fetch prof.students as stud
order by stud.name

我收到了错误：严重：org.springframework.dao.InvalidDataAccessResourceUsageException：无法执行查询;

我的订单是否可以通过？或者hibernate映射不允许这样的请求？

Answer 1

从查询中删除Distinct关键字。然后，如果您需要消除重复项，请使用ResultTransformer为您合并结果集。

String hql = "select prof from Professor as prof left join fetch prof.students as stud order by stud.name"; 
Query query = session.createQuery(hql)
                     .setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);

hql request：manytomany集合属性的订单列表结果

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