What's new in SQL Server 2016: CREATE OR ALTER

SQL Server 2016 Service Pack 1 added the CREATE OR REPLACE functionality, however in SQL Server, it is called CREATE OR ALTER.  Finally it is here, this has been asked for since the 90s, it was on the SQL Server wishlist (who remembers that before they had connect :-)

CREATE OR ALTER can be used with the following four object types

STORED PROCEDURES
FUNCTIONS
TRIGGERS
VIEWS

Let's take a look how this all works

If you want to run this code, you need to be on SQL Server 2016 Service pack 1 or higher or on vNext, the @@VERSION function on SP1 and vNext returns the following


Microsoft SQL Server 2016 (SP1) (KB3182545) - 13.0.4001.0 (X64)   Oct 28 2016 18:17:30
Microsoft SQL Server vNext (CTP1) - 14.0.1.246 (X64)   Nov  1 2016 23:24:39


Before they added CREATE OR ALTER, you had  a couple of options to create rerunable scripts. The first way was dropping the proc if it existed and having the CREATE PROC in the same script, it looked like this

--old way of dropping a proc then having a create script
IF OBJECT_ID('procTest') is not null
DROP PROCEDURE procTest
GO

CREATE PROCEDURE procTest
AS
BEGIN
 PRINT (1)
END;
GO

Another way would be to create a dummy proc if the proc didn't exist already and then just have the ALTER PROC part in your script

--another way is to have a dummy proc created,
--that way your alter part is always the same
IF OBJECT_ID('dbo.procTest') IS NULL
  EXEC ('CREATE PROCEDURE dbo.procTest AS RETURN 0;')
GO

ALTER PROCEDURE  procTest
AS
BEGIN
 PRINT (1)
END;
GO

In SQL Server 2016 with Service Pack 1, this becomes so much easier. Here is what it looks like

-- the easier way in sql server 2016 SP1 and up
CREATE OR ALTER PROCEDURE procTest
AS
BEGIN
 PRINT (1)
END;
GO

Here is how that looks with a function, pretty much the same as a procedure

-- works the same with functions
CREATE OR ALTER FUNCTION fnTest()
RETURNS INT
AS
BEGIN
 RETURN(1)
END;
GO

The view looks like this

-- also works with views
CREATE OR ALTER VIEW vwTest
AS
 SELECT 1 AS col;
GO

With triggers it is pretty much the same, here is the code that you can run, I first created a table otherwise I would not be able to create a trigger

-- first we need a table for the trigger
IF NOT EXISTS(SELECT * FROM sys.tables WHERE name = 'BooFar')
CREATE TABLE BooFar(id int)
GO

-- works with triggers
CREATE OR ALTER TRIGGER trTest
ON BooFar
AFTER INSERT, UPDATE
AS
 RAISERROR ('Hello from trigger', 1, 10);
 GO

 -- just a test to make sure the trigger works
 INSERT BooFar values(1)

 -- you should see this in the message tab
 /*
Hello from trigger
Msg 50000, Level 1, State 10

(1 row(s) affected)
*/

The CREATE OR REPLACE syntax does NOT work with DDL triggers. If you execute this the first time it will run fine.

CREATE OR ALTER TRIGGER safety   
ON DATABASE   
FOR DROP_TABLE, ALTER_TABLE   
AS   
   PRINT 'You must disable Trigger "safety" to drop or alter tables!'   
   ROLLBACK;  

Now run it again, you will get this error

Msg 2714, Level 16, State 2, Procedure safety, Line 1 [Batch Start Line 77]
There is already an object named 'safety' in the database.

So be aware that CREATE OR ALTER does not work with DDL triggers

I submitted a connect item for this: https://connect.microsoft.com/SQLServer/feedback/details/3111866

I want them to either disable CREATE OR ALTER for DDL triggers or they should fix it so it doesn't error on a second run


Tor wrap this up, let's drop all these objects we just created, we will do that by using the Drop if exists syntax

--  drop everything by using
--  DROP object IF EXISTS
DROP TABLE IF EXISTS  BooFar
DROP PROCEDURE IF EXISTS  procTest
DROP VIEW IF EXISTS  vwTest

You can find the github repo for the series here whatisnewinsqlserver2016, all the code for this post can be found here CREATE Or ALTER