请教一个mysql查询问题,送上100分
本帖最后由 SHANDIANDIAN 于 2013-12-12 12:15:27 编辑
表A 表B
uid mid cash uid mid cash number
1 1 100 1 1 101 100
2 2 105 2 1 100 100
3 3 98 3 2 105 200
4 4 55 4 2 105 300
5 5 60 5 3 60 300
6 6 70 6 3 98 300
uid 是自动增长字段 mid和cash 是关联字段
我想统计出 表B的求和数量就和下面这样,没匹配到表A就显示0,匹配通过mid和cash 两字段。请问SQL该怎么写?? 以表A为基础表
结果表
uid mid cash number
1 1 100 100
2 2 105 500
3 3 98 300
4 4 55 0
5 5 60 0
6 6 70 0
------解决方案--------------------你太调皮,后来编辑过帖子了
看这个
http://sqlfiddle.com/#!2/9847b/12
------解决方案--------------------create temporary table A
select 1 as uid, 1 as mid, 100 as cash
union select 2, 2, 105
union select 3, 3, 98
union select 4, 4, 55
union select 5, 5, 60
union select 6, 6, 70;
create temporary table B
select 1 as uid, 1 as mid, 101 as cash,&