How to check if a stored procedure exists before c

Question

I have a SQL script that has to be run every time a client executes the "database management" functionality. The script includes creating stored procedures on the client database. Some of these clients might already have the stored procedure upon running the script, and some may not. I need to have the missing stored procedures added to the client database, but it doesn't matter how much I try to bend T-SQL syntax, I get

CREATE/ALTER PROCEDURE' must be the first statement in a query batch

I've read that dropping before creating works, but I don't like doing it that way.

IF EXISTS (SELECT * FROM sys.objects WHERE type = 'P' AND name = 'MyProc')
DROP PROCEDURE MyProc
GO

CREATE PROCEDURE MyProc
...

How can I add check for the existence of a stored procedure and create it if it doesn't exist but alter it if it does exist?

Answer 1

Here's a method and some reasoning behind using it this way. It isn't as pretty to edit the stored proc but there are pros and cons...

UPDATE: You can also wrap this entire call in a TRANSACTION. Including many stored procedures in a single transaction which can all commit or all rollback. Another advantage of wrapping in a transaction is the stored procedure always exists for other SQL connections as long as they do not use the READ UNCOMMITTED transaction isolation level!

1) To avoid alters just as a process decision. Our processes are to always IF EXISTS DROP THEN CREATE. If you do the same pattern of assuming the new PROC is the desired proc, catering for alters is a bit harder because you would have an IF EXISTS ALTER ELSE CREATE.

2) You have to put CREATE/ALTER as the first call in a batch so you can't wrap a sequence of procedure updates in a transaction outside dynamic SQL. Basically if you want to run a whole stack of procedure updates or roll them all back without restoring a DB backup, this is a way to do everything in a single batch.

IF NOT EXISTS (select ss.name as SchemaName, sp.name as StoredProc 
    from sys.procedures sp
    join sys.schemas ss on sp.schema_id = ss.schema_id
    where ss.name = 'dbo' and sp.name = 'MyStoredProc')
BEGIN
    DECLARE @sql NVARCHAR(MAX)

    -- Not so aesthetically pleasing part. The actual proc definition is stored
    -- in our variable and then executed.
    SELECT @sql = 'CREATE PROCEDURE [dbo].[MyStoredProc]
(
@MyParam int
)
AS
SELECT @MyParam'
    EXEC sp_executesql @sql
END

Answer 2

I wonder! Why i don't write the whole query like

GO
create procedure [dbo].[spAddNewClass] @ClassName varchar(20),@ClassFee int
as
begin
insert into tblClass values (@ClassName,@ClassFee)
end

GO
create procedure [dbo].[spAddNewSection] @SectionName varchar(20),@ClassID       int
as
begin
insert into tblSection values(@SectionName,@ClassID)
end

Go
create procedure test
as
begin 
select * from tblstudent
end

i already know that first two procedures are already exist sql will run the query will give the error of first two procedures but still it will create the last procedure SQl is itself taking care of what is already exist this is what i always do to all my clients!

Answer 3

DROP IF EXISTS is a new feature of SQL Server 2016

https://blogs.msdn.microsoft.com/sqlserverstorageengine/2015/11/03/drop-if-exists-new-thing-in-sql-server-2016/

DROP  PROCEDURE IF EXISTS dbo.[procname]

Answer 4

I realize this has already been marked as answered, but we used to do it like this:

IF NOT EXISTS (SELECT * FROM sys.objects WHERE type = 'P' AND OBJECT_ID = OBJECT_ID('dbo.MyProc'))
   exec('CREATE PROCEDURE [dbo].[MyProc] AS BEGIN SET NOCOUNT ON; END')
GO

ALTER PROCEDURE [dbo].[MyProc] 
AS
  ....

Just to avoid dropping the procedure.

Answer 5

I had the same error. I know this thread is pretty much dead already but I want to set another option besides "anonymous procedure".

I solved it like this:

1. Check if the stored procedure exist:

   IF NOT EXISTS (SELECT * FROM sysobjects WHERE name='my_procedure') BEGIN
       print 'exists'  -- or watever you want
   END ELSE BEGIN
       print 'doesn''texists'   -- or watever you want
   END
   

2. However the "CREATE/ALTER PROCEDURE' must be the first statement in a query batch" is still there. I solved it like this:

   SET ANSI_NULLS ON
   GO
   SET QUOTED_IDENTIFIER ON
   GO
   
   CREATE -- view procedure function or anything you want ...
   

3. I end up with this code:

   IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = OBJECT_ID('my_procedure'))
   BEGIN
       DROP PROCEDURE my_procedure
   END
   
   SET ANSI_NULLS ON
   GO
   SET QUOTED_IDENTIFIER ON
   GO
   
   CREATE PROCEDURE [dbo].my_procedure ...
   

Answer 6

In addition to the answer from @Geoff I've created a simple tool which generates a SQL-file which statements for Stored Procedures, Views, Functions and Triggers.

See MyDbUtils @ CodePlex.