Creating a stored procedure using variables - sql

Question

Is there any good way to do this, or am I just heading in the wrong direction? I would like to create a stored procedure inside an SQL script. I would like to have variables declared at the beginning of the script so that I can create the SPROCs to use in different contexts/servers.Here is what I would like to do (I know this obviously doesn't work, but I'm looking for any ideas of an alternative)..
DECLARE #golbalValue = 'SomeValue'
GO
CREATE PROCEDURE [dbo].[MyStoredProcedure](
AS
BEGIN
SELECT * FROM Mytable WHERE MyCol = #globalValue
END
GO

Answer 1

What you could do is use a scalar function for the variable
create function f ()
returns varchar(20)
as
begin
return 'some value'
end
go
then use it in your procedure
create proc p ()
as
begin
select *
from my_table
where col = f()
end
go
another possibility which is perhaps more appropriate is to use sqlcmd here's an example.

Answer 2

From what I understand, you need to create stored procedures with set value from your parameters. You don't want input parameters in the stored Procedures though. Second, you want to switch database contexts. So I think you'll need a tempTable for your parameters and some dynamic SQL. Try this out:
IF OBJECT_ID('tempdb..#globalParam') IS NOT NULL
DROP TABLE #globalParam;
IF OBJECT_ID('AdventureWorks2012.dbo.myTable') IS NOT NULL
DROP TABLE AdventureWorks2012.dbo.myTable
IF OBJECT_ID('Master..myTable') IS NOT NULL
DROP TABLE Master..mytable
--Create your data tables
SELECT 'SomeValue' AS col1 INTO AdventureWorks2012.dbo.myTable;
SELECT 1000 AS col1 INTO master.dbo.myTable;
CREATE TABLE #globalParam(
ParamName VARCHAR(100),
val SQL_VARIANT --SQL_Variant is designed to hold all data types.
);
--Here are your globalParams
DECLARE #globalParam1 VARCHAR(100) = 'SomeValue';
DECLARE #globalParam2 INT = 1000;
--Load your parameters into a table. Might have to cast some of your parameters to SQL_Variant
INSERT INTO #globalParam
VALUES ('globalParam1',#globalParam1),
('globalParam2',CAST(#globalParam2 AS sql_variant));
GO
--Switch database context
USE AdventureWorks2012
GO
--Variable to hold CREATE PROC
DECLARE #sql VARCHAR(MAX);
--Set #SQL with parameter value from #globalParam
SELECT #sql =
'CREATE PROCEDURE dbo.myStoredProc AS
BEGIN
SELECT * FROM myTable WHERE col1 = ''' + CAST(val AS VARCHAR(100)) + '''
END'
FROM #globalParam
WHERE ParamName = 'globalParam1'
--Execute to create the stored procedure
EXEC(#sql)
--Execute it to see if it works
EXEC dbo.myStoredProc
--Switch context. Repeat same steps
USE master
GO
DECLARE #sql VARCHAR(MAX);
SELECT #sql =
'CREATE PROCEDURE dbo.myStoredProc AS
BEGIN
SELECT * FROM myTable WHERE col1 = ''' + CAST(val AS VARCHAR(100)) + '''
END'
FROM #globalParam
WHERE ParamName = 'globalParam2'
EXEC(#sql)
EXEC dbo.myStoredProc
--Cleanup
DROP PROCEDURE dbo.myStoredProc;
USE AdventureWorks2012
GO
DROP PROCEDURE dbo.myStoredProc;

Answer 3

You cannot do what you want. T-SQL doesn't have the concept of global variables. One method is to store values in a "global" table and then reference them as needed. Something like:
create table GlobalParams (
name varchar(255) not null primary key,
value varchar(255) not null
);
create procedure . . .
begin
. . .
declare #value varchar(255);
select #value = value from Globalparams where name = 'name';
select *
from Mytable
where MyCol = #value;
. . .
end;
Note: this is a simplistic example that only allows variables whose type is a string.
You can also wrap the logic in a user-defined function, so the call looks like:
select *
from Mytable
where MyCol = udf_GlobalLookup('name');
It is rather rare to need global parameters that are shared among different stored procedures. Such a global context can be useful, at times, for complex systems. It is unlikely that you need all this machinery for a simple application. An alternative method, such as just passing the parameters in as arguments, is probably sufficient.