Using Stored Procedures - Beginning C# 2008 Databases: From Novice to Professional - page 101

Figure 6-4. Using an output parameter
How It Works
You add an output parameter, @ordercount, assigning a default value of zero.
create procedure sp_Orders_By_EmployeeId2
@employeeid int,
@ordercount int = 0 output
as
select orderid,customerid
from orders
where employeeid = @employeeid;
The keyword output marks it as an output parameter.
You also add an additional query.
select @ordercount = count(*)
from orders
where employeeid = @employeeid