ssrs multivalue parameter stored procedure

Question

I have a report im creating in SSRS (2008) and the data for the report is coming from a stored procedure in MS SQL.

I want to have a multiple value parameter (done this

Answer 1

I feel your pain, we had the same issue when using SSRS with SP's. You do indeed need to split out the values you are passing to the stored procedure.

In your stored Procedure SQL is expecting;

 Alias.Field1 IN (@RC) 

Which compiles down to

Alias.Field1 IN ('Value1','Value2,'Value3')

However, SSRS will pass the parameter values as one long string (why MS did is beyond me) and will end up being this

Alias.Field1 IN ('Value1,Value2,Value3')

Which, as you correctly pointed out, you have zero control over. So you need to use a Split Strings function. Aaron Bertrand did a great blog post on this one over at SQLPerformance.com which gives you the pros and cons of each method based on the size of your database. We used the SplitStrings CTE as it gave the best performance for the size of most of our DBs.

Here is the function;

CREATE FUNCTION [dbo].[fn_SplitStringsCTE]
(
   @List       NVARCHAR(MAX),
   @Delimiter  NVARCHAR(255)
)
RETURNS @Items TABLE (Item NVARCHAR(4000))
WITH SCHEMABINDING
AS
BEGIN
   DECLARE @ll INT = LEN(@List) + 1, @ld INT = LEN(@Delimiter);

   WITH a AS
   (
       SELECT
           [start] = 1,
           [end]   = COALESCE(NULLIF(CHARINDEX(@Delimiter, 
                       @List, 1), 0), @ll),
           [value] = SUBSTRING(@List, 1, 
                     COALESCE(NULLIF(CHARINDEX(@Delimiter, 
                       @List, 1), 0), @ll) - 1)
       UNION ALL
       SELECT
           [start] = CONVERT(INT, [end]) + @ld,
           [end]   = COALESCE(NULLIF(CHARINDEX(@Delimiter, 
                       @List, [end] + @ld), 0), @ll),
           [value] = SUBSTRING(@List, [end] + @ld, 
                     COALESCE(NULLIF(CHARINDEX(@Delimiter, 
                       @List, [end] + @ld), 0), @ll)-[end]-@ld)
       FROM a
       WHERE [end] < @ll
   )
   INSERT @Items SELECT [value]
   FROM a
   WHERE LEN([value]) > 0
   OPTION (MAXRECURSION 0);

   RETURN;
END
GO

And here is how you implement it in your Stored Procedure;

AND (Alias.Field1 IN (SELECT Item FROM [dbo].[fn_SplitStringsCTE](@RC,',')))

As for passing NULLs to the Stored Procedure, this is also something we wanted to do but instead decided to use the following, and then adding a value to you SSRS parameter that passes 'All Values', it was a nice catch-all for us when we wanted to return all the values of that parameter, but if you have NULLs in your dataset they will also need to be handled.

AND (@RC = 'All Values' OR Alias.Field1 IN (SELECT Item FROM [dbo].[fn_SplitStringsCTE](@RC,',')))