sql - 代码错误。未使用EXISTS引入子查询时，只能在选择列表中指定一个表达式

Question

我正在尝试运行此查询，但是无论我做什么，我都会不断收到此错误，但无法解决。任何帮助，将不胜感激。

select
  CC.ContactID, 

from 
  Client C 
  join Contacts CC on CC.ContactID = C.ContactID 
 where 

        ClientID In (
    
                                  Select 
                                    ClientID,Sum(Total-allocated) as Bal 
                                  from 
                                    Main 
                                  Where 
                                    Total <> Allocated
                                    and NomTypeID < 10 
                                  Group By 
                                    ClientID
                                  HAVING Sum(Total-allocated) > 10
                             )

Answer 1

我不确定您使用的是哪种数据库(因此我也无法测试我的答案)。
但是通常，当您使用IN时，您需要子查询仅返回一列。
因此查询应为(删除了Sum(Total-allocated) as Bal):

select
  CC.ContactID, 

from 
  Client C 
  join Contacts CC on CC.ContactID = C.ContactID 
 where 

        ClientID In (
    
                                  Select 
                                    ClientID 
                                  from 
                                    Main 
                                  Where 
                                    Total <> Allocated
                                    and NomTypeID < 10 
                                  Group By 
                                    ClientID
                                  HAVING Sum(Total-allocated) > 10
                             )