Calling stored procedure from other stored procedure - sql

Question

This is stored procedure #1:
ALTER PROCEDURE [dbo].[sp1]
AS
BEGIN
DECLARE #test varchar(255)
exec #test = dbo.sp2
SET NOCOUNT ON;
SELECT
CMS_ORG.description, #test
FROM
CMS_ORG
END
This is stored procedure #2:
ALTER PROCEDURE [dbo].[sp2]
AS
BEGIN
SET NOCOUNT ON;
SELECT
CMS_MAS.description + '' + CONVERT(varchar(50),
CAST(CMS_ORG.amount AS money), 1)
FROM
CMS_ORG
INNER JOIN
CMS_MAS = CMS_ORG.GUID = CMS_MAS.GUID
END
The problem is here is I was not able to execute #test in stored procedure #1 by calling the stored procedure #2. When I execute sp1, I got a null values instead but when I execute the query of sp2 in sp1, I got a correct value. May I know what is the possible solution or similar examples which can solve the issue?

Answer 1

Your stored proc sp2 outputs the result of a SELECT, but like all stored procs, it returns an integer using the return statement. You don't have a return statement, so Sql Server generates one for you: return 0. The purpose of the return code is to give feedback on whether it ran as expected. By convention, a return code of 0 means no errors.
This shows the difference between the return code and the output of a stored proc. Create a temp table #output to capture the rows of the SELECT that the stored proc outputs.
DECLARE #return_code int
-- capture the output of the stored proc sp2 in a temp table
create table #output( column_data varchar(max) )
insert #output( column_data )
exec #return_code = dbo.sp2 -- returns 0 because you have no RETURN statement
-- extract column_data from #output into variable #test
-- if there is more than one row in #output, it will take the last one
DECLARE #test varchar(255)
select #test = column_data from #output

Answer 2

Create a table variable & Use it like this :
create proc test55
as
select 55
declare #test table (Value Varchar(255))
insert into #test
exec test55
Select * from #test

Answer 3

Your sp2 stored procedure will return table, not varchar(255).
If you want to get a varchar(255) from sp2 you should be using function.
You can view in my example:
Define a function:
CREATE FUNCTION dbo.function1()
RETURNS varchar(255)
WITH EXECUTE AS CALLER
AS
BEGIN
DECLARE #returnVal varchar(255);
SET #returnVal = (SELECT top 1 [ProductName]
FROM [dbo].[Products])
RETURN(#returnVal);
END;
And alter SP1 like this:
ALTER PROCEDURE [dbo].[sp1]
#SMonth As Integer,
#SYear As Integer
AS
BEGIN
DECLARE #test varchar(255)
set #test = dbo.function1()
SET NOCOUNT ON;
SELECT [ProductId], #test
FROM [LearningKO].[dbo].[Products]
END