Ask how this SQL is written and how to handle it

Ask this SQL for the wording
This post was last edited by u011669689 on 2013-09-25 18:25:00

Basic conditions:
User Table UserID, username
User_money Table U_id,user_money
User_money_exchange table: Money, Username,ordertag = 1 or 2

Now want to do:

Update User_money Set User_money = (User_money_exchange when Ordertag =1 's sum (money) + when Ordertag =2 's sum (money)) where User_mo ney.u_id = User.userid

(select SUM (Ume.money) as M, U.userid from User_money_exchange Ume left  join user u on ume.username = U.username wher e Ume.ordertag = 1 GROUP BY Ume.username

Select SUM (Ume.money) as M, U.userid from User_money_exchange ume  

where user_money.u_id = U.userid

This is wrong, and you want to know what's right? Thank you, everyone. SQL Select Update

Share to:

------Solution--------------------
Give it a try

Update User_money um left join user u on Um.u_id=u.userid
Left Join  
(select Username,sum (Money) as moneys from User_money_exchange Group by username) Ume
On Ume.username=u.username
Set Um.money = Ume.moneys

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