MySQl Sum（Count（）-Count（）函数

Question

嗨，我需要弄清楚为什么我的代码的最后一部分将无法运行。

任何帮助都会很棒。

SELECT
xxxx,
  xxxx,
   xxxxy,

   COUNT(xxxx) * xxxx AS Driver_fees,
   COUNT(xxxx) * xxxx AS Revenue,

-- 'This section will not run' 
   SUM((COUNT((xxxx) * xxxx)) -
   (COUNT((xxxx) * xxxx))) AS Gross_Profit

FROM
   xxxx INNER JOIN xxxx ON xxxx` = xxxx
   WHERE week = 11 AND day ='Sunday'
   GROUP BY week, date

Answer 1

假设Gross_Profit = Revenue - Driver_fees，您实际上并不想在此查询中使用SUM

COUNT(xxxx) * yyyy AS Driver_fees,
COUNT(wwww) * zzzz AS Revenue,
COUNT(wwww) * zzzz - COUNT(xxxx) * yyyy AS Gross_Profit