Question

我有一个使用GROUP BY X的SELECT。它在投影中使用SUM。有没有办法对SUM进行排序？具有最高值的组结果应该在结果表中排在第一位。我怀疑没有办法对这个SUM进行排序，因为当每个组完成它的输出并且消失了;没有任何“集合”可以排序。我必须在这里做一些完全不同的事情。你有任何提示吗？

谢谢。

（初级）

Answer 1

如果我理解你的问题，答案很简单：

SELECT customer, SUM(amount) FROM mytable GROUP BY customer ORDER BY SUM(amount);

Answer 2

I'm not sure you meant this but here is an example

assume that there is data in a table which shows payments people have made to a bank. 
But people pay different money in different times.

*id*  *payment*  *time*
 1      10      01 04 2016
 2      20      01 02 2016
 1      35      14 03 2016
 3      22      21 01 2016
 2      50      01 04 2016


Now you want to calculate who has paid max money.

SELECT person_id, MAX(payment) AS totalPayment
from payments
group by person_id
ORDER BY totalPayment DESC

使用GROUP BY选择，您可以按投影的SUM进行排序吗？

2 个答案: