select (select sum(cost) from a where id=xxx) ys, (select sum(cost) from b where id=xxx) yf, ys-yf from abc
我这么写貌似是错的，必须再写一遍两个子查询用减号相连么？
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参考文档
› http://mysql-python.sourceforge.net/MySQLdb.html
This topic created in 3593 days ago, the information mentioned may be changed or developed.
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1
petelin Jul 13, 2016 via Android
可以考虑 join
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2
delavior Jul 13, 2016
必须再嵌套一层，定义的别名在同一个 select 里肯定是无效的
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3
petelin Jul 13, 2016
`select a.sum - a.sum from (select id,sum(in_money) as sum from A where id = 0) as a,(select id,sum(out_money) as sum from B where id = 0) as b;`
`select (select sum(in_money) from A where id = 0) - (select sum(out_money) from B where id = 0);` |
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