无法对包含聚合或子查询的表达式执行聚合函数的 SQL 错误

Question

我在 SQL 中执行此查询，但出现类似“无法对包含聚合或子查询的表达式执行聚合函数”的错误。有没有人可以帮助我。我真的被困住了。谢谢 这是我的查询。

SELECT [id]
      ,[name]
      ,SUM(case 
           when [code] = 1  Then 
           case 
             when exists(select * from [sampletab] where [id] = [id]and [code] = 2) then

                case when exists(select * from [sampletab] where [id] = [id] and [code] = 4) then 100 
                else 100
                end 

               else 100
               end    
           when [code] = 8 then 200
           when code = 2 then 100
           when code = 4 then 100

      end
      ) as "totl"

  FROM [test].[dbo].[sampletab]
  GROUP BY id , name

My data

Answer 1

这是您的查询的一个版本，实际上应该会得到一些结果。

SELECT
Id,
Name,
SUM(ScorePerCode)
FROM (
    SELECT 
    id,
    name,
    CASE WHEN code = 1 THEN 100
        WHEN code = 2 THEN 50
        WHEN code = 4 THEN 20
        WHEN code = 8 THEN 200
        END AS ScorePerCode
    FROM [test].[dbo].[sampletab]
) X
GROUP BY Id, Name

您查询的这一部分毫无意义，是您问题的根源。如果这个查询有机会工作的话，你总是会得到 100 的值...

 WHEN [code] = 1
         THEN 
            CASE WHEN EXISTS ( SELECT * FROM [sampletab] WHERE [code] = 2 ) 
            THEN 
                CASE WHEN EXISTS ( SELECT * FROM [sampletab] WHERE [code] = 4) 
                THEN 100
                ELSE 100 END 
            ELSE 100 END