Creating a stored procedure if it does not already exist

Pro-level insights and advice

Have a backup plan with error handling

Like an SQL superhero, sometimes you need a cape. In this case, your cape is the use of TRY...CATCH statements for those pesky errors that may occur during procedure creation. This will ensure a swift rollback if necessary, maintaining your database integrity. This is your secret weapon against chaos in the database universe.

BEGIN TRY
    BEGIN TRANSACTION;
    
   /* Think - "I am the One" */
    IF OBJECT_ID('dbo.YourProcedureName', 'P') IS NULL
    BEGIN
        EXEC('CREATE PROCEDURE dbo.YourProcedureName AS BEGIN /* Mighty SP code commences here */ END');
    END

    COMMIT TRANSACTION;
END TRY
BEGIN CATCH
    ROLLBACK TRANSACTION;
    /* Error! You've entered the Matrix! */
END CATCH


Keeping your permissions intact

Be a Jedi master of your metadata and permissions by avoiding the reckless dropping of procedures. Instead, master the way of the CREATE OR ALTER, a less destructive path that keeps your procedure untouched. The Force is strong with SQL Server 2016 SP1, that supports this approach.

CREATE OR ALTER PROCEDURE dbo.YourProcedureName
AS
BEGIN
   /* May the SQL be with you */
    /* Your SP code */
END


Showing-off your scripting talents with dynamic SQL

In a galaxy where syntactical correctness is of paramount importance, dynamic SQL is your trusted droid for error-free and adaptable SQL operations.

EXEC sp_executesql N'
IF NOT EXISTS (SELECT * FROM sys.objects WHERE type = ''P'' AND name = ''YourProcedureName'')
BEGIN
    /* R2-D2 says Beep-boop-beep! Let's make a new procedure! */
    EXEC(''CREATE PROCEDURE dbo.YourProcedureName AS BEGIN /* SP code powered by the Force */ END'');
END
'


Deploy like a SQL Avenger

When you're on the front lines, deploying your scripts, especially in production, deploying like an Avenger is the ultimate winning strategy:

• Use your Ironman-like intellect to check if an object exists before you alter or drop it.
• Be the Captain America of database integrity by diligently using BEGIN, COMMIT, and ROLLBACK.
• Think like Black Widow – always have a commit or rollback as your exit strategy.
• Ant-Man knows size matters and so does the inclusion of grant statements in your scripts.

Deep dives and error prevention

Embracing placeholders

While waiting for your final procedure instructions from SHIELD (your boss), you might need to occupy the space with a placeholder procedure. Just tweak the SET NOEXEC ON/OFF settings like a true SQL superhero.

IF OBJECT_ID('dbo.PartialProcedure', 'P') IS NULL
BEGIN
    SET NOEXEC ON;
    EXEC('CREATE PROCEDURE dbo.PartialProcedure AS BEGIN /* WATCH THIS SPACE: Under Construction! */ END');
    SET NOEXEC OFF;
END


Avoiding unnecessary procedure demise

In your quest against redundancy, tread lightly when using DROP PROCEDURE IF EXISTS. It's best kept for cases of unwanted procedures, promising their safe farewell.

DROP PROCEDURE IF EXISTS dbo.OldProcedure;
/* Goodbye old friend, your watch has ended */


Propelling accuracy with OBJECT_ID

Command precision with OBJECT_ID, ensuring a quick and reliable way to validate a stored procedure's existence, avoiding error snags like a true superhero.

IF OBJECT_ID('dbo.ProcedureToCheck', 'P') IS NOT NULL
    PRINT 'Procedure exists!';
/* I have both eye on you */


Harnessing dynamic SQL and idempotence

Real superheroes can bend rules, even in SQL. Harness dynamic SQL for intricate and fluid conditions, and for scripts to remain idempotent (run repeatedly without duplicating effects), CREATE OR ALTER is your infinity stone.