如果您对支持多个观察的帮助表值函数感兴趣，如果您不需要该函数，将逻辑迁移到CROSS APPLY中也是小事一桩

• • 示例**

Declare @YourTable Table ([Col1] varchar(50))  Insert Into @YourTable Values 
 ('Mark(1234)')
,('6789')
,('VZ(X678)')
,('ASD(5677)qwe')
 
Select A.* 
      ,NewValue = coalesce(RetVal,Col1)
 from @YourTable A
 Outer Apply [dbo].[tvf-Str-Extract](Col1,'(',')') B

• • 结果**

Col1            NewValue
Mark(1234)      1234
6789            6789
VZ(X678)        X678
ASD(5677)qwe    5677

• • 结果**

CREATE FUNCTION [dbo].[tvf-Str-Extract-JSON] (@String nvarchar(max),@Delim1 nvarchar(100),@Delim2 nvarchar(100))
Returns Table 
As
Return (  

    Select RetSeq = row_number() over (order by RetSeq)
          ,RetVal = left(RetVal,charindex(@Delim2,RetVal)-1)
    From  (
            Select RetSeq = [Key]+1
                  ,RetVal = trim(Value)
             From  OpenJSON( N'["'+replace(string_escape(@String,'json'),@Delim1,'","')+N'"]' )

          ) C1
    Where charindex(@Delim2,RetVal)>1

)

• • 编辑-无TVF**

Select A.* 
      ,NewValue = coalesce(RetVal,Col1)
 from @YourTable A
 Outer Apply (
                Select RetSeq = row_number() over (order by RetSeq)
                      ,RetVal = left(RetVal,charindex(')',RetVal)-1)
                From  (
                        Select RetSeq = [Key]+1
                              ,RetVal = trim(Value)
                         From  OpenJSON( N'["'+replace(string_escape(Col1,'json'),'(','","')+N'"]' )

                      ) C1
                Where charindex(')',RetVal)>1
             ) B

@martin Smith谢谢你指出通配符的用法。我把我的代码修改成这样，它做了我需要它做的事情！使用case when表达式来查找括号，而不管位置如何，所以我保留了%通配符，但在CHARINDEX中去掉了它，正如你提到的：

SELECT DISTINCT col1,
CASE WHEN col1 like '%(%' then
SUBSTRING (col1,
        CHARINDEX('(', col1) + 1,
        CHARINDEX(')', col1) - CHARINDEX('(', col1) - 1)
        else col1 end
from MyTable B;