是这样的一个情况 这里有三张表 分别是用户user，订单 trade ，和资金记录 user_money_record
现在要根据用户来统计他们的订单总金额和账户余额以及充值总金额
user表
id realname money
1 张xx 100
2 王xx 500
3 李xx 1500
trade
id uid realmoney
1 2 5000
2 1 1000
3 2 5000
4 3 10000
5 1 3500
user_money_record
id uid money
1 2 5000
2 1 5000
3 2 2000
4 2 3000
5 3 5000
6 3 5000
表结构及数据如上
求统计他们的订单总金额和账户余额以及充值总金额
谢谢！
如果user表的信息是最完整的，应该是这样的：
SELECT *
FROM (SELECT id, sum(money) FROM user GROUP BY id) t1
LEFT JOIN (SELECT id, sum(realmoney) FROM trade GROUP BY id) t2 ON t1.id = t2.id
LEFT JOIN (SELECT id, sum(money) FROM user_money_record GROUP BY id) t3 ON t1.id = t3.id我猜想你可能是要这样的
Holbird select u.name,t.realmoney,umr.money from user u
left join
(select uid,sum(realmoney) as realmoney from trade group by uid) t on t.uid = u.id
left join
(select uid,sum(money) as money from user_money_record group by uid) umr on umr.uid = uid对于这样的情况 假如数据量过大的情况如何处理
Graves 
大树 
