使用特定值计算Distinct Paycheck

Question

我有这张表MyTable：

 Amount       Desc  Month Sym code  ID
 ------------------------------------------
 $32,323.00   Bla1    1   121 3   2424221
  $4,242.00   Bla1    1   121 3   2424221
 $32,323.00   Bla2    2   124 3   2424221
  $4,242.00   Bla2    2   124 3   2424221
 $32,323.00   Bla2    3   124 3   2424221
  $4,242.00   Bla3    1   126 3   2424221
  $3,535.00   Bla3    2   126 1   3230824
  $4,984.00   Bla4    1   433 1   3230824
 $47,984.00   Bla4    2   433 1   3230824
     $41.00   Bla4    2   433 1   3230824
  $3,472.00   Bla5    1   D2  27  2297429
  $3,472.00   Bla5    1   D2  27  2297429
  $3,239.00   Bla5    2   D2  27  2297429
  $3,472.00   Bla6    1   A2  27  2297429
  $3,239.00   Bla6    1   A2  27  2297429
  $3,239.00   Bla6    6   A2  27  3332321
  $3,239.00   Bla6    6   A2  27  3332321
  $4,249.00   Bla8    1   114 24  3434334
  $4,249.00   Bla8    2   114 24  3434334
  $4,249.00   Bla8    7   114 24  3434334
  $4,249.00   Bla8    7   114 24  3434334

我如何计算一个sym出现在员工身上的数量？ （至少一次......意思 - 如果它在jan中7次 - 一次，在feb中8次 - 一次等）

Answer 1

您可以先GROUP BY月和Sym，然后计算行数：

SELECT COUNT(*) AS NumberMonths121, SUM(Amount) SumAmount121 FROM (
  SELECT Month, Sym, COUNT(*) AS Amount
  FROM MyTable
  WHERE Sym=121
  GROUP BY Month,Sym
) AS subquery;