sql - 如何在选择查询中使用别名并将它们加在一起

Question

我在下面有以下查询。我想使用别名并将它们加在一起，但 SQL 不允许这样做。关于如何在不重复查询的情况下解决这个问题的任何建议？使用 Microsoft SQL Server 2008

SELECT    
SUM(CASE WHEN rg.category = 'Space' THEN ((rg.score*20)) END) As space,
SUM(CASE WHEN rg.category = 'QPR' THEN ((rg.score*20)) END) As qpr,

(space + qpr) As result
FROM rg_fin As rg JOIN...../*query goes on*/

Answer 1

您可以将查询包装为子查询

SELECT *,
  (space + qpr) As result 
FROM
(
  SELECT     
  SUM(CASE WHEN rg.category = 'Space' THEN ((rg.score*20)) END) As space, 
  SUM(CASE WHEN rg.category = 'QPR' THEN ((rg.score*20)) END) As qpr
  ....
 ) subquery