两个表 求SQL
表1
UserId Capital
1 50
2 60
3 70
表2
UserId Price Vol
1 1.8 50
1 3.6 20
2 2.4 70
3 6.2 10
2 1.3 30
表2要按UserId 去更新表1的Capital。。。。(Capital = Price * Vol)
[解决办法]
create table 表1(UserID int,Capital money)create table 表2(UserID int,Price money,Vol int)goinsert 表1select 1,50 unionselect 2,60 unionselect 3,70insert 表2select 1,1.8,50 unionselect 1,3.6,20 unionselect 2,2.4,70 unionselect 3,6.2,10 unionselect 2,1.3,30 update 表1 set Capital=表1.Capital+b.Capital from (select UserID,SUM(Price*Vol) Capital from 表2 group by UserID)b where 表1.UserID=b.UserID select * from 表1 /* UserID Capital1 212.002 267.003 132.00*/drop table 表1drop table 表2