Question

执行时我有以下这一行，给我这个错误。我如何使用此处存在过滤行'next_NotedID'？在此先感谢

 Msg 116, Level 16, State 1, Line 27
    Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.

这是我的where子句

 where (Name = 'File Review' and next_Name = 'File Review')
                                                 and   (TYPECODE ='1200005' and next_Typecode = '1200005')
                                                 and   ((HEADLINE like '%Follow up letter%')
                                                        and (next_Headline like '%Follow up letter%'))
                                                  and next_NotedID <>  (SELECT  ParentRef, max(NoteID)from Stg.IG_Note group by PARENTREF)

Answer 1

您可以将subquery与相关联：

. . .
and next_NotedID <> (SELECT max(nt.NoteID) 
                     from Stg.IG_Note nt 
                     where nt.PARENTREF = outerqueryalise.ParentRef
                     );

如果您与内部查询next_NotedID的{{1}}进行比较，那么您可以直接将其表达为

max(NoteID)

Answer 2

更改此行：

and next_NotedID <>  (SELECT  ParentRef, max(NoteID)from Stg.IG_Note group by PARENTREF)

为：

and next_NotedID <>  (SELECT  max(NoteID)from Stg.IG_Note group by PARENTREF)

使用＆lt;＆gt;时，您无法在子选择中选择多于1个字段。如果这会返回多于一个可能的值，则需要将其更改为NOT IN而不是＆lt;＆gt;

在子查询中使用group by

2 个答案: