如何在mysql中找到一个字段和组的最大值

Question

我有下表有4列，我想要最多count1并按sname分组。 count1的最大值给了我最大值，但当我按sname进行分组时，它会使用错误的cname和sname。       我期待的是s1 c2 30和s2 c1 40.任何人都可以帮我解决mysql查询

Answer 1

SELECT g.sname AS sname, g.cname AS cname, g.count1 AS total 
FROM giriya AS g
   INNER JOIN (SELECT cname, MAX(count1) AS countMax GROUP BY cname) AS ss
   ON g.cname = ss.cname AND g.count1 = ss.countMax

Answer 2

SELECT g.sname，g.cname，g.count1 AS total FROM giriya AS g INNER JOIN（来自giriya GROUP BY cname的SELECT cname，MAX（count1）AS countMax）AS ss  ON g.cname = ss.cname和g.count1 = ss.countMax