mysql - 如何在 1 个查询中选择 sum() 多列？

Question

只是样本表：Cus_fi。

我可以吗

SELECT SUM(dollar,euro,pound) FROM cus_fi ; in 1 query.

并像这样按年龄范围显示结果。

   20 - 25   1500    410     166
   26 - 30   5300    2000    584

感谢帮助学生真的很想知道。

Answer 1

select
    round(age / 5) * 5 - 4,
    round(age / 5) * 5,
    SUM(dollar),
    SUM(euro)
FROM TEST
GROUP BY round(age / 5)

您可以使用更多列来扩展它。见演示：http ://sqlfiddle.com/#!2/160bb/15

Answer 2

试试这个：

SELECT age, SUM(dollar) AS Total_Dollar, SUM(Euro) AS Total_Euro, 
SUM(Pound) AS Total_Pound 
    FROM cus_fi GROUP BY age

编辑：

SELECT CONCAT(2*floor(age/2), '-', 2*floor(age/2) + 2) as `age_range`, SUM(dollar) AS Total_Dollar, SUM(Euro) AS Total_Euro, 
SUM(Pound) AS Total_Pound 
    FROM cus_fi GROUP BY 1 ORDER BY age