连接表时，MySQL选择SUM

Question

SELECT u.user_id, u.website, u.phone, SUM( r.redeem_amount ) , SUM( r.redeem_paid )
FROM users u
LEFT JOIN redeemed r ON u.user_id = r.redeem_user_id
WHERE r.redeem_state = '0'
GROUP BY u.website

What am trying to do, is to select the SUM of redeem amount from table redeem against each website, each website should be selected it's total (SUM) from redeem table

The provided query is able to select each website but failing to select SUM from table redeem as it is select only one row from redeem not total of that website.

Can I have your help or be pointed where am getting things wrong and how I can improve this. I know to some you may fee it simple but I can't get the trick as am not too advanced in MySQL.

http://sqlfiddle.com/#!9/9eecb7d

Answer 1

Well, Try to use the below :

SELECT u.user_id, u.website, u.phone, SUM( r.redeem_amount ) , SUM( r.redeem_paid ) FROM users u LEFT JOIN redeemed r ON u.user_id = r.redeem_user_id WHERE r.redeem_state = '0' GROUP BY r.redeem_user_id