3,333,300),
(4,111,101),
(5,111,102),
(6,222,201),
(7,222,202),
(8,333,301),
(9,333,302);
##DEMO1:找出最大的金额...:
"id" "order_no" "max(amt)"
"1" "111" "102"
"2" "222" "202"
"3" "333" "302"
**/
##DEMO2:根据每个订单号找出ID最大的一行记录...SELECT t.* FROM (
SELECT * FROM `test_user` ORDER BY id DESC
) t GROUP BY order_no
##找出最大的这一条记录数
##方法