hql查询从每个组中检索前n个 [英] hql query to retrieve top n from each group

问题描述

我想在HQL中实现以下功能 -

从table1中选择top n其中table1.id IN（某些选择子查询）

我已经找到了setMaxResult（n）方法，但它只能检索整个结果的前n个字段，但是我想实现的是每个小组的前n ...

感谢...

解决方案

这里是您需要的JPQL：

从雇员中选择a
where
（
）选择来自员工的计数（*）b
其中
a.department = b.department和
a.salary <= b.salary
）<= 10
按工资排序DESC


i want to achieve the following in HQL -

select top n from table1 where table1.id IN (some select sub query)

i have found the setMaxResult(n) method, but it can only retrieve top n of the entire result.. but what i want to achieve is top n of each group...

Thanks...

解决方案

Here is JPQL you need:

select a from Employee a
where
(
    select count(*) from Employee b
    where 
       a.department = b.department and
       a.salary <= b.salary
) <= 10
order by salary DESC

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