我想過濾一個特定列的 MYSQL 查詢

Question

我正在嘗試過濾，所以salaryMonth列只包含里面有2020數據，所以2019被過濾掉了。

SELECT sum(km_amount) as total
     , user_id
     , salaryMonth 
  from kms
     , users 
 where users.id = kms.user_id 
 group 
    by salaryMonth
     , user_id 

Answer 1

你有沒有嘗試過這樣的事情？

SELECT
    sum(km_amount) as total, 
    user_id, 
    salaryMonth 
FROM kms, users 
WHERE
    users.id=kms.user_id 
    AND salaryMonth LIKE '%2020%' 
GROUP BY 
    salaryMonth, user_id 

Answer 2

將你的表重構為：

total user_id salary_yearmonth
  625      64 2020-02-01 
  595      70 2020-02-01 
  600      74 2020-02-01
  632      75 2020-02-01
  471      77 2020-02-01
  788      29 2019-03-01
   35       4 2020-03-01
   22      39 2020-03-01
  373      47 2020-03-01
  196      53 2020-03-01
  140      74 2020-03-01
  228      75 2020-03-01
   49      29 2019-04-01 
   96      63 2019-05-01 
  406       4 2019-06-01 
  966       4 2019-07-01 
  514       1 2019-08-01 
  637       4 2019-08-01
  580      47 2019-08-01
   11       1 2019-09-01