mysql limit inside group?

Question

I want to limit the size of records inside a group, and here is my trial, how to do it right?

mysql> select * from accounts limit 5 group by type;
         


        

Answer 1

Try placing the LIMIT clause after the GROUP BY clause.

EDIT: Try this:

SELECT * 
FROM accounts a1
WHERE 5 > 
(
   SELECT COUNT(*)
   FROM accounts a2
   WHERE a2.type = a1.type
   AND a2.balance > a1.balance
)

This returns at most 5 accounts of each type with the biggest balances.