SQL Stored Procedures for SQL Server
What is a Stored Procedure?
A stored procedure is a prepared SQL code that you can save, so the code can be reused over and over again.
So if you have an SQL query that you write over and over again, save it as a stored procedure, and then just call it to execute it.
You can also pass parameters to a stored procedure, so that the stored procedure can act based on the parameter value(s) that is passed.
Stored Procedure Syntax
CREATE PROCEDURE procedure_name
AS
sql_statement
GO;
Execute a Stored Procedure
EXEC procedure_name;
Demo Database
Below is a selection from the "Customers" table in the Northwind sample database:
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 |
Alfreds Futterkiste | Maria Anders | Obere Str. 57 | Berlin | 12209 | Germany |
| 2 | Ana Trujillo Emparedados y helados | Ana Trujillo | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno Taquería | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico |
| 4 |
Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK |
| 5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |
Stored Procedure Example
The following SQL statement creates a stored procedure named "SelectAllCustomers" that selects all records from the "Customers" table:
Example
CREATE PROCEDURE SelectAllCustomers
AS
SELECT * FROM Customers
GO;
Execute the stored procedure above as follows:
Example
EXEC SelectAllCustomers;
Stored Procedure With One Parameter
The following SQL statement creates a stored procedure that selects Customers from a particular City from the "Customers" table:
Example
CREATE PROCEDURE SelectAllCustomers @City nvarchar(30)
AS
SELECT * FROM Customers WHERE City = @City
GO;
Execute the stored procedure above as follows:
Example
EXEC SelectAllCustomers @City = 'London';
Stored Procedure With Multiple Parameters
Setting up multiple parameters is very easy. Just list each parameter and the data type separated by a comma as shown below.
The following SQL statement creates a stored procedure that selects Customers from a particular City with a particular PostalCode from the "Customers" table:
Example
CREATE PROCEDURE SelectAllCustomers @City nvarchar(30), @PostalCode nvarchar(10)
AS
SELECT * FROM Customers WHERE City = @City AND PostalCode = @PostalCode
GO;
Execute the stored procedure above as follows:
Example
EXEC SelectAllCustomers @City = 'London', @PostalCode = 'WA1 1DP';
