How to return temporary table from stored procedure

Question

CREATE PROCEDURE [test].[proc]
@ConfiguredContentId int,
@NumberOfGames int
AS
BEGIN
 SET NOCOUNT ON
 RETURN 
 @WunNumbers TABLE (WinNumb int)

    INSERT INTO @WunN         


        

Answer 1

First create a real, permanent table as a template that has the required layout for the returned temporary table, using a naming convention that identifies it as a template and links it symbolically to the SP, eg tmp_SPName_Output. This table will never contain any data.

In the SP, use INSERT to load data into a temp table following the same naming convention, e.g. #SPName_Output which is assumed to exist. You can test for its existence and return an error if it does not.

Before calling the sp use this simple select to create the temp table:

SELECT TOP(0) * INTO #SPName_Output FROM tmp_SPName_Output;
EXEC SPName;
-- Now process records in #SPName_Output;

This has these distinct advantages:

• The temp table is local to the current session, unlike ##, so will not clash with concurrent calls to the SP from different sessions. It is also dropped automatically when out of scope.
• The template table is maintained alongside the SP, so if changes are made to the output (new columns added, for example) then pre-existing callers of the SP do not break. The caller does not need to be changed.
• You can define any number of output tables with different naming for one SP and fill them all. You can also define alternative outputs with different naming and have the SP check the existence of the temp tables to see which need to be filled.
• Similarly, if major changes are made but you want to keep backwards compatibility, you can have a new template table and naming for the later version but still support the earlier version by checking which temp table the caller has created.