mysql - 如何在 mySQL 中使用 SUM？

Question

我需要为我的查询求和一个组。像这样的东西:

SELECT customer_id, SUM(weekly) FROM earnings GROUP BY customer_id

上面的工作，但我需要一些更复杂的东西，我的查询是这样的:

SELECT
    (SELECT SUM(weekly) FROM earnings) + 
    (SELECT SUM(day_earnings) FROM earnings) / .75

上面是所有收入的总和，每周和每天，但我需要在第一个示例中按 customer_id 对它们进行分组。我如何实现这一点？

Answer 1

根据您在上述尝试中的操作顺序，只有 SUM(day_earnings) 除以 .75。如果它应该是每周和 day_earnings 总和，则将它们放在括号中作为 (SUM(weekly) + SUM(day_earnings))/0.75 AS earnings。

SELECT 
  customer_id,
  customer_name,
  SUM(weekly) + SUM(day_earnings) / 0.75 AS earnings
FROM earnings JOIN customers ON earnings.customer_id = customers.customer_id
GROUP BY customer_id, customer_name