hql query to retrieve top n from each group

问题

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...

回答1:

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

来源：https://stackoverflow.com/questions/4264528/hql-query-to-retrieve-top-n-from-each-group