Introduction to Stored Procedures in SQL Server

The Stored Procedures saves a collection of one or group of statements saved in the SQL Server. Here, we explain to you How to create, rename, alter, and delete Stored Procedures in SQL Server with examples. The following are benefits of using them

  • All the SQL Server Stored Procedures are pre-compiled, and their execution plan is cached. So, when you execute the same one again, it will use the cache.
  • It will help you to encapsulate the business rules and policies. For example, database admin will create a procedure, and multiple users will access the procedure from JAVA, C#PythonR, etc.
  • Instead of sending hundreds of lines of code, it is better to use a stored procedure. So that, we can call the single statement (it’s name), rather than writing the complex statement or sending it over the network.
  • The SQL server stored procedures helps you to access the database objects in a more secure and uniform way
  • Network bandwidth conservation (protect from harm or delay)

I suggest you refer the following examples to understand the SQL Server Stored procedures in detail:

  • SELECT to understand, How to write the SELECT Statements inside it
  • INSERT article to follow the steps involved in writing the INSERT Statements inside it.
  • UPDATE to write the UPDATE Statements inside it.
  • Input Parameters to declare and use the input Parameter, including single parameter value or multiple parameters.
  • Output Parameters: The output parameters are useful to output the values.
  • Return Values
  • Temporary Tables: Create temporary procedures that includes the local temporary procedure or global temporary procedure.

Before we get into the practical example, let us see the syntax.

SQL Stored Procedures Syntax

The basic syntax of SQL Server stored procedure is as shown below:

CREATE [OR ALTER] PROCEDURE [Schema_Name].Procedure_Name
                @Parameter_Name Data_type, 
                .... 
                @Parameter_Name Data_type
AS
   BEGIN
      -- Query
      -- SELECT, Insert, Update, Or Delete Statements
      -- You can Use CTE also 
   END

Let me explain the syntax:

  • Schema_name: Please specify the schema name. For example, dbo, or Humanresource, etc.
  • Procedure_Name: You can specify any stored procedure name you wish to give other than the system reserved keywords. Please try to use meaningful names so that you can identify them quickly.
  • @Parameter_Name: Every stored procedure accepts zero or more parameters, completely depends upon the user requirements. While declaring the parameters don’t forget the appropriate data type. For example (@FullName VARCHAR(50), @Age INT)

Create Stored Procedures in SQL Server

Forgot to mention, we can create them in two ways, and the data that we use for this demonstration

Employee Table 0

Create SQL Stored Procedures using Management Studio

Before we start creating any, let us see whether our database had any existing ones. To view the existing ones, Please select the Database -> Programmability -> Stored procedures. From the below screenshot, you can observe that our database has none.

Right-click on the Stored Procedures folder will open the context menu. Please select the New -> Stored Procedure..option from it.

Create a New Stored Procedures in SQL Server 1

Once you click on the New option it will open the new Query window with default Template

Auto Generated SQL Stored Procedure 2

Here, you can add the name, Parameters (if required), and the Procedure or transact query you want to use.

Create SQL Stored Procedures using Query

In this example, we show how to create SP using the Create Procedure Statement

CREATE PROCEDURE SelectingAllRecordsInEmployee 
AS
BEGIN

 SET NOCOUNT ON;
 SELECT [FirstName]
              ,[LastName]
              ,[Education]
              ,[Occupation]
              ,[YearlyIncome]
              ,[Sales]
              ,[HireDate]
 FROM [Employee]
END
GO

Output

Messages
--------
Command(s) completed successfully.

As you can see that, the command has completed successfully. The following screenshot shows the simple Stored Procedure that we created earlier.

View SP

Execute Stored Procedure in SQL Server

We can execute sp in two ways:

Execute using SQL Server Management Studio

To execute SQL Server Stored Procedure using the Management Studio (SSMS), Please navigate to the Programmability -> SP. Next, select the one that you want to execute (SelectingAllRecordsInEmployee), and right-click on it will open the context menu. Please, choose the Execute option

Execute SQL Stored Procedure 5

Once you select the Execute option, an Execute Procedure window will open. If the procedure has any parameters, we have to assign/pass those values and click OK to execute. Here, our sp does not have any parameters so, click OK to execute the procedure

Execute Procedure General Tab

Once you click on the OK button, a new query window opened with the following auto-generated code

DECLARE @return_value int

EXEC @return_value = [dbo].[SelectingAllRecordsInEmployee]

SELECT 'Return Value' = @return_value

GO
Execute SQL Stored Procedure result 7

Execute

Execute SQL Server Stored Procedure using the EXEC Command (Execute Command)

EXEC  [dbo].[SelectingAllRecordsInEmployee]
Select records from sp using EXEC

Rename Stored Procedure in SQL Server

There is no such thing called renaming the Stored procedure. Because renaming it will not change its corresponding object name within the sys.sql_modules. So, if you want to rename any existing sp, then DROP and recreate it with a new name.

-- Renaming SP
-- Check whether there is a SP with the Following Name
IF OBJECT_ID ( 'SelectingAllRecordsInEmployee', 'P' ) IS NOT NULL   
    -- If so, Drop that Procedure
     DROP PROCEDURE SelectingAllRecordsInEmployee;  
GO  

-- Creating  SP with New name
CREATE PROCEDURE SelectingEmployeeRecords 
AS
BEGIN

 SET NOCOUNT ON;
 SELECT [FirstName]
          ,[LastName]
          ,[Education]
          ,[Occupation]
          ,[YearlyIncome]
          ,[Sales]
          ,[HireDate]
 FROM [Employee]
END
GO

output

Messages
-------
Command(s) completed successfully.

From the below screenshot, see we successfully deleted the old one, and created the completely new.

View SQL Stored Procedure 10

Modify Stored Procedure in SQL Server

The following examples help you learn the steps to change them using the Management Studio (SSMS) and query.

Change using SSMS

To alter using the SQL Server Management Studio, right-click on the name (SelectingEmployeeRecords) that you want to change, and select the Modify option

Modify SQL Stored Procedure 11

Once you choose the option, a new query window opened with auto-generated ALTER PROCEDURE code. You can change as per your requirement.

Altter Procedure Query Gnerated by the Management Studio

Use Alter to Modify Stored Procedure in SQL Server

This example will show you the steps involved in modifying the existing one using the ALTER PROCEDURE statement. To do so, Click New query and return the following query.

ALTER PROCEDURE [dbo].[SelectingEmployeeRecords] 
AS
BEGIN
 SET NOCOUNT ON;
 SELECT [FirstName]
              ,[LastName]
              ,[Education]
              ,[Occupation] AS Profession
              ,[YearlyIncome]
             ,[Sales]
 FROM [Employee]
END

Run the above alter query

Messages
--------
Command(s) completed successfully.

Let us execute the above to check whether we successfully changed or not.

EXEC [dbo].[SelectingEmployeeRecords]
GO
EXEC procedure result

Delete Stored Procedure in SQL Server

The following examples will show you, How to delete or drop the SQL Stored Procedures using the Transact Query and Management Studio (SSMS).

Delete using Management Studio

In this example, we will show how to delete Stored Procedures using the SSMS or Management Studio. To do so, Please navigate to the one that you want to delete. Next, right-click on the procedure name to open the context menu. You can click on the Delete option as shown below

Delete SQL Stored Procedure 15

For this SQL stored procedure demonstration, we are going to delete SelectingEmployeerecords. Once you select the delete option, a Delete Object window will open as shown below. Click on the Show Dependencies button to check the dependencies, and then click OK to delete it.

Delete Object window

Delete or Drop

In this example, we show you how to drop or delete using a query.

IF OBJECT_ID ( 'SelectingEmployeeRecords', 'P' ) IS NOT NULL   
    DROP PROCEDURE SelectingEmployeeRecords;  
GO

TIP: It is good practice to check, whether the name or sp exists in the database or not using IF OBJECT_ID (N’Stored_Procedure_Name’, ‘P’) IS NOT NULL

SQL Stored Procedures Best Practices

The following is a list of suggestions that might help you to improve the SQL Server stored procedures performance.

  • Try to use the Schema Names while you were creating or referencing any database object. It will decrease the database engine processing time.
  • Always specify the required column names within the SELECT Statement. And avoid the SELECT * Statement
  • While Creating or altering a table using (CREATE TABLE or ALTER TABLE), use the DEFAULT keyword to assign the default values to the Columns. It will prevent the NULL values, and assign those default values to the column data.
  • When you are creating Temporary Tables inside the sp, You have to specify whether the Column accepts NULLS, or NOT explicitly. It can be done by using NULL, or NOT NULL
  • Rather than Extracting, or Inserting a large amount of data, try to work with less and essential data. It reduces the query processing load, and increase the query performance.
  • Use the SET NOCOUNT ON statement within the SQL server stored procedure. It will turn off the messages that are sent by the SQL Server to the Client. It includes the number of rows updated, deleted, etc.
  • Try to replace the UNION Operator, or OR Operator with the UNION ALL Operator, unless you are looking for distinct values.
  • If possible, avoid using the SCALAR Functions in the SELECT statement that returns a large amount of data. It is because the scalar function applied on each row (row basic), so it will affect the query performance.
  • To handle the errors, SQL allows us to use the TRY CATCH feature inside the Stored Procedures. So, try to use the TRY CATCH feature
  • Always use the BEGIN..COMMIT TRANSACTION within the SP. Remember that the transaction should be as short as possible. Otherwise, there is a danger in either deadlock or longer locking.

Best Approach to create Stored Procedures

It will be an ideal way to create in real-time

IF OBJECT_ID ( 'SelectingEmployeeRecords', 'P' ) IS NOT NULL   
    DROP PROCEDURE SelectingEmployeeRecords;  
GO
CREATE PROCEDURE SelectingEmployeeRecords 
AS
BEGIN

 SET NOCOUNT ON;
 SELECT [FirstName]
          ,[LastName]
          ,[Education]
          ,[Occupation]
          ,[YearlyIncome]
          ,[Sales]
          ,[HireDate]
 FROM [Employee]
END
GO

Encrypted Stored Procedure

By adding the WITH ENCRYPTION keyword, we can create the encrypted Stored Procedure. For example, if we add the below line in the above query

CREATE PROCEDURE SelectingEmployeeRecords 
WITH ENCRYPTION
AS
BEGIN
....
........

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