Overview
In a previous topic we discussed how to pass parameters into a stored procedure, but another option is to pass parameter values back out from a stored procedure.  One option for this may be that you call another stored procedure that does not return any data, but returns parameter values to be used by the calling stored procedure.
Explanation
Setting up output paramters for a stored procedure is basically the same as setting up input parameters, the only difference is that you use the OUTPUT clause after the parameter name to specify that it should return a value.  The output clause can be specified by either using the keyword "OUTPUT" or just "OUT".
Simple Output

CREATE PROCEDURE uspGetAddressCount @City nvarchar(30), @AddressCount int OUTPUT AS SELECT @AddressCount = count(*) FROM AdventureWorks.Person.Address WHERE City = @City

Or it can be done this way:

CREATE PROCEDURE uspGetAddressCount @City nvarchar(30), @AddressCount int OUT AS SELECT @AddressCount = count(*) FROM AdventureWorks.Person.Address WHERE City = @City

To call this stored procedure we would execute it as follows.  First we are going to declare a variable, execute the stored procedure and then select the returned valued.

DECLARE @AddressCount int EXEC uspGetAddressCount @City = 'Calgary', @AddressCount = @AddressCount OUTPUT SELECT @AddressCount

This can also be done as follows, where the stored procedure parameter names are not passed.

DECLARE @AddressCount int
EXEC uspGetAddressCount 'Calgary', @AddressCount OUTPUT
SELECT @AddressCount