mysql - 组功能本身很好，但组合在一起就不行了？

Question

我有一个 mysql 查询，看起来像这样:

SELECT
   SUM(reg_yr) AS reg_yr_total,
   SUM(spot_as_reg_yr) AS spot_as_reg_yr_total
FROM foo
WHERE bar
GROUP BY baz
ORDER BY reg_yr_total

效果很好。如果我想将 ORDER BY 子句更改为 reg_yr_total+spot_as_reg_yr_total但是，我收到一条错误消息 Reference 'reg_yr_total' not supported (reference to group function) .

为什么我可以单独使用这些列中的每一列，但是当我尝试将这两列添加到一起时却失败了？有办法解决这个问题吗？

Answer 1

如果您不想选择另一列，请尝试以下操作:

SELECT
   SUM(reg_yr) AS reg_yr_total,
   SUM(spot_as_reg_yr) AS spot_as_reg_yr_total
FROM foo
WHERE bar
GROUP BY baz
ORDER BY SUM(reg_yr) + SUM(spot_as_reg_yr)