Question

mysql将一个表中有相同字段值的记录合并

表ABC：
id m1 m2
1 aaaa 1
2 bbbb 1
3 aaaa 1
4 aaaa 1
5 bbbb 1
合并为：
1 aaaa 3
2 bbbb 2
合并后,并按m2排序（从大到小）

Answer 1

select m1, sum(m2) from ABC group by m1;

Answer 2

select m1, sum(m2) from ABC group by m1 order by desc;