Returning SQL Server stored procedure parameter values to a calling stored procedure

 

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". For these examples we are still using the AdventureWorks database, so all the stored procedures should be created in the AdventureWorks database.

Simple Output

CREATE PROCEDURE dbo.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 dbo.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 dbo.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 dbo.uspGetAddressCount 'Calgary', @AddressCount OUTPUT
SELECT @AddressCount

Creating a simple SQL Server stored procedure

 

Overview

As mentioned in the tutorial overview a stored procedure is nothing more than stored SQL code that you would like to use over and over again.  In this example we will look at creating a simple stored procedure.

Explanation

Before you create a stored procedure you need to know what your end result is, whether you are selecting data, inserting data, etc..

In this simple example we will just select all data from the Person.Address table that is stored in the AdventureWorks database.

So the simple T-SQL code excuting in the AdventureWorks database would be as follows which will return all rows from this table.

SELECT * FROM Person.Address

To create a stored procedure to do this the code would look like this:

USE AdventureWorks
GO

CREATE PROCEDURE dbo.uspGetAddress
AS
SELECT * FROM Person.Address
GO

To call the procedure to return the contents from the table specified, the code would be:

EXEC dbo.uspGetAddress
-- or
EXEC uspGetAddress
--or just simply
uspGetAddress

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When creating a stored procedure you can either use CREATE PROCEDURE or CREATE PROC.  After the stored procedure name you need to use the keyword "AS" and then the rest is just the regular SQL code that you would normally execute.

One thing to note is that you cannot use the keyword "GO" in the stored procedure.  Once the SQL Server compiler sees "GO" it assumes it is the end of the batch.

Also, you can not change database context within the stored procedure such as using "USE dbName" the reason for this is because this would be a separate batch and a stored procedure is a collection of only one batch of statements.