我有2张表
a
字段
1.UserName(Varchar) 2.Number(int)
b
1.UserName(Varchar)
我要实现 a表中的Number中的总数
条件是 b表中的UserName 等于 a表中的UserName获得结果
UserName Number 结果例如
------------------------
UserName Number
zhangsan 1200
a
字段
1.UserName(Varchar) 2.Number(int)
b
1.UserName(Varchar)
我要实现 a表中的Number中的总数
条件是 b表中的UserName 等于 a表中的UserName获得结果
UserName Number 结果例如
------------------------
UserName Number
zhangsan 1200
update a set number=count(1)
from a join b on a.username=b.username
group by a.username
select a.UserName,sum(a.Number)
from a left join b
on a.UserName=b.UserName
group by a.UserName
select a.UserName,sum(Number) as Number from a join b on a.UserName=b.UserName group by a.UserName
(select UserName, sum(Num) as TotalNum from A表 group by UserName) as b
where a.UserName=b.UserName
--#5楼条件漏了