Question

I’m working on a report in reporting services that has the user select a number of items from a multivalue list. The query for the report uses the resulting list in a simple

SELECT foo FROM bar WHERE foobar IN (@SelectedItemsFromMultiValueList)

I’m now altering the report and need to iterate over the items in @SelectedItemsFromMultiValueList using a cursor. I’ve looked around but can’t figure out how to do this – made even more difficult by the fact that I’m not sure what to call a list of values used in an IN or even declare one manually (eg. DECLARE @SelectedItemsFromMultiValueList ???)

Does anybody know how to cursor over a multivalue list parameter or how to call something like that in SQL so I can search more effectively for a solution?

Answer 1

Your multi-value list is going to come in to sql as a list of comma separated values (i.e. “31,26,17”)

To iterate through these values you need a way to split the values into a table. This is a function I have used, that I believe was originally coded by Jens Suessmeyer:

CREATE FUNCTION [dbo].[ufn_split]
   (  @Delimiter varchar(5), 
      @List      nvarchar(max)
   ) 
   RETURNS @TableOfValues table 
      (  RowID   smallint IDENTITY(1,1), 
         [Value] NVARCHAR(max)
      ) 
AS 
   BEGIN

      DECLARE @LenString int 

      WHILE len( @List ) > 0 
         BEGIN 

            SELECT @LenString = 
               (CASE charindex( @Delimiter, @List ) 
                   WHEN 0 THEN len( @List ) 
                   ELSE ( charindex( @Delimiter, @List ) -1 )
                END
               ) 

            INSERT INTO @TableOfValues 
               SELECT substring( @List, 1, @LenString )

            SELECT @List = 
               (CASE ( len( @List ) - @LenString ) 
                   WHEN 0 THEN '' 
                   ELSE right( @List, len( @List ) - @LenString - 1 ) 
                END
               ) 
         END

      RETURN 

   END 

So you call this function, passing it @SelectedItemsFromMultiValueList and it will return to you a table of values that you can then do with what you want.

For example:

SELECT * FROM Foo WHERE X IN (SELECT [value] FROM dbo.ufn_split(',', @SelectedItemsFromMultiValueList)