How to check if a stored procedure exists before creating it

问题:

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?

回答1:

You can run procedural code anywhere you are able to run a query.

Just copy everything after AS:

BEGIN     DECLARE @myvar INT     SELECT  *     FROM    mytable     WHERE   @myvar ... END 

This code does exactly same things a stored proc would do, but is not stored on the database side.

That's much like what is called anonymous procedure in PL/SQL.

Update:

Your question title is a little bit confusing.

If you only need to create a procedure if it not exists, then your code is just fine.

Here's what SSMS outputs in the create script:

IF EXISTS ( SELECT  *             FROM    sys.objects             WHERE   object_id = OBJECT_ID(N'myproc')                     AND type IN ( N'P', N'PC' ) )  DROP … CREATE … 

Update:

Example of how to do it when including the schema:

IF EXISTS ( SELECT *              FROM   sysobjects              WHERE  id = object_id(N'[dbo].[MyProc]')                     and OBJECTPROPERTY(id, N'IsProcedure') = 1 ) BEGIN     DROP PROCEDURE [dbo].[MyProc] END 

In the example above, dbo is the schema.

回答2:

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.

回答3:

If you're looking for the simplest way to check for a database object's existence before removing it, here's one way (example uses a SPROC, just like your example above but could be modified for tables, indexes, etc...):

IF (OBJECT_ID('MyProcedure') IS NOT NULL)   DROP PROCEDURE MyProcedure GO 

This is quick and elegant, but you need to make sure you have unique object names across all object types since it does not take that into account.

I Hope this helps!

回答4:

As of SQL SERVER 2016 you can use the new DROP PROCEDURE IF EXISTS.
DROP { PROC | PROCEDURE } [ IF EXISTS ] { [ schema_name. ] procedure } [ ,...n ]

Reference : https://msdn.microsoft.com/en-us/library/ms174969.aspx

回答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 ... 

回答6:

I know you want to "alter a procedure if it exists and only delete it if it does not exist" but I believe it's simpler to just always drop the procedure and then re-create it. Here's how to drop the procedure only if it already exists:

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

The second parameter tells OBJECT_ID to only look for objects with object_type = 'P', which are stored procedures:

AF = Aggregate function (CLR)

C = CHECK constraint

D = DEFAULT (constraint or stand-alone)

F = FOREIGN KEY constraint

FN = SQL scalar function

FS = Assembly (CLR) scalar-function

FT = Assembly (CLR) table-valued function

IF = SQL inline table-valued function

IT = Internal table

P = SQL Stored Procedure

PC = Assembly (CLR) stored-procedure

PG = Plan guide

PK = PRIMARY KEY constraint

R = Rule (old-style, stand-alone)

RF = Replication-filter-procedure

S = System base table

SN = Synonym

SO = Sequence object

TF = SQL table-valued-function

You can get the full list of options via:

SELECT name  FROM master..spt_values WHERE type = 'O9T' 

回答7:

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 

回答8:

I know it is a very old post, but since this appears in the top search results hence adding the latest update for those using SQL Server 2016 SP1 -

create or alter procedure procTest as begin  print (1) end; go 

This creates a Stored Procedure if does not already exist, but alters it if exists.

Reference

回答9:

I apparently don't have the reputation required to vote or comment, but I just wanted to say that Geoff's answer using EXEC (sp_executesql might be better) is definitely the way to go. Dropping and then re-creating the stored procedure gets the job done in the end, but there is a moment in time where the stored procedure doesn't exist at all, and that can be very bad, especially if this is something that will be run repeatedly. I was having all sorts of problems with my application because a background thread was doing an IF EXISTS DROP...CREATE at the same time another thread was trying to use the stored procedure.

回答10:

**The simplest way to drop and recreate a stored proc in T-Sql is **

Use DatabaseName go If Object_Id('schema.storedprocname') is not null begin    drop procedure schema.storedprocname end go  create procedure schema.storedprocname as  begin end 

回答11:

Check IF Exist For Stored Procedure

IF EXISTS (SELECT * FROM sys.objects              WHERE object_id = OBJECT_ID              (N'[Schema].[Procedure_Name]') AND type IN (N'P', N'PC')) BEGIN        DROP PROCEDURE [Schema].[Procedure_Name]        Print('Proceudre dropped => [Schema].[Procedure_Name]') END 

Check IF Exist for Trigger , Function also by clicking below link http://www.gurujipoint.com/2017/05/check-if-exist-for-trigger-function-and.html

回答12:

why don't you go the simple way like

    IF EXISTS(SELECT * FROM sys.procedures WHERE NAME LIKE 'uspBlackListGetAll')     BEGIN          DROP PROCEDURE uspBlackListGetAll     END     GO      CREATE Procedure uspBlackListGetAll 

..........

回答13:

In Sql server 2008 onwards, you can use "INFORMATION_SCHEMA.ROUTINES"

IF EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.ROUTINES    WHERE ROUTINE_NAME = 'MySP'         AND ROUTINE_TYPE = 'PROCEDURE')  

回答14:

Here is the script that I use. With it, I avoid unnecessarily dropping and recreating the stored procs.

IF NOT EXISTS (     SELECT *     FROM sys.objects     WHERE object_id = OBJECT_ID(N'[dbo].[uspMyProcedure]')     ) BEGIN   EXEC sp_executesql N'CREATE PROCEDURE [dbo].[uspMyProcedure] AS select 1' END GO  ALTER PROCEDURE [dbo].[uspMyProcedure]      @variable1 INTEGER   AS BEGIN    -- Stored procedure logic END 

回答15:

This is the standard way of creating a data base when you're adding new elements and don't want to disrupt the existing entities.

回答16:

If you need to modify a stored procedure before each launch, then maybe you can store its text as mere text in a varchar(max) column and execute it using sp_executesql.

Although I can't see why ALTER PROCEDURE would be worse than that.

回答17:

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.

回答18:

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!

回答19:

CREATE Procedure IF NOT EXISTS 'Your proc-name' () BEGIN ... END

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