Question

我有一个看起来像这样的mysql查询：

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，我会收到一条错误，指出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，但是一旦我尝试将它们加在一起就会失败？有办法解决这个问题吗？

Answer 1

如果您不想选择其他列，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)

Answer 2

尝试将它们汇总到另一个虚拟列：

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

这是未经测试的，但应该有用。

如果这是一个错误的答案，请告诉我，我很乐意将其删除。

群组本身功能正常，但加在一起时却没有？

2 个答案: