数据库字符串截取

Create Function [dbo].[Func_SplitStr]
(
     @InputStr NVARCHAR(max),
     @SplitSymbol NVARCHAR(max) = ','
) 
Returns @Func_SplitStr table
(
     val nvarchar(max)
) 
as
Begin

     Declare @str varchar(max)
     Declare @substr varchar(max)
     Declare @iLen int
     Declare @iStart int
     set @str=RTrim(Ltrim(@InputStr))

     set @iStart=CHARINDEX( @SplitSymbol , @str )
     set @iLen=Len( @str )
     IF @iStart>0
     Begin
           set @substr=substring( @str , 1 , @iStart-1 )
           set @str=substring( @str , @iStart+1 , @iLen-@iStart )
     End
     Else
     Begin
           set @substr=@str
           set @str=''
     End

     set @substr=RTRIM( LTRIM( @substr ) )
     insert @Func_SplitStr select id=cast( @substr as nvarchar )


     While Len( @str )>0
     Begin
     ---------------- Loop Begin ---------------

     set @iStart=CHARINDEX(  @SplitSymbol , @str )
     set @iLen=Len( @str )
     IF @iStart>0
     Begin
           set @substr=substring( @str , 1 , @iStart-1 )
           set @str=substring( @str , @iStart+1 , @iLen-@iStart )
     End
     Else
     Begin
           set @substr=@str
           set @str=''
     End

     set @substr=RTRIM( LTRIM( @substr ) )
     insert @Func_SplitStr select id=cast( @substr as nvarchar )
      ---------------- Loop End ----------------
     End 
Return
End  

　　select * from dbo.Func_SplitStr('a,b,c,d,1,2',',')