兩列之和的劃分

Question

我需要把兩列的總和除以總數。兩列都是十進制數據類型。這是我迄今爲止所沒有的。

SELECT total_salary/DistEnroll 
FROM dbo.vw_Salary 
WHERE DistEnroll = (
      SELECT DISTINCT(distenroll) 
      FROM dbo.vw_Salary 
      WHERE YEAR = '2012' 
        AND dist_name = 'Sch Dist' 
     ) 
     AND total_salary = (
       SELECT SUM(total_salary) 
       FROM [vw_salary] 
       WHERE YEAR = '2012' 
         AND dist_name = 'Sch Dist' 
      ) 

Answer 1

select 
     (select sum(total_salary) 
     from [vw_salary] 
     where year = '2012' 
     and dist_name = 'Sch Dist') --totalsal 
    /
     (select count(distinct distenroll) 
     from dbo.vw_Salary 
     where year = '2012' 
     and dist_name = 'Sch Dist') -- DistEnroll 

，或者更好：

 select sum(total_salary)/count(distinct distenroll) 
     from [vw_salary] 
     where year = '2012' and 
       dist_name = 'Sch Dist'