SQL Server supports temporary tables(local and global).
Using dynamic-SQL (EXEC or dbo.sp_executesql) we could create new context and local temporary table is visible only in dynamic-SQL block but not outside.
-- Normal table
EXEC ('CREATE TABLE tab(i INT); INSERT INTO tab(i) VALUES (1)');
SELECT * FROM tab;
-- Global temporary table
EXEC ('CREATE TABLE ##tab(i INT); INSERT INTO ##tab(i) VALUES (2)');
SELECT * FROM ##tab;
-- Local temporary table
EXEC ('CREATE TABLE #tab(i INT); INSERT INTO #tab(i) VALUES (3)');
SELECT * FROM #tab;
-- Invalid object name '#tab'.
LiveDemo
Now let's try the same with stored procedures:
-- Normal procedure
EXEC ('CREATE PROCEDURE my_proc AS SELECT 1 AS col;');
EXEC my_proc;
-- Global temporary procedure
EXEC ('CREATE PROCEDURE ##my_proc AS SELECT 2 AS col;');
EXEC ##my_proc;
-- Local temporary procedure
EXEC ('CREATE PROCEDURE #my_proc AS SELECT 3 AS col;');
EXEC #my_proc;
LiveDemo2
The question is why local temporary procedure behaves differently and it is visible outside EXEC?
The reason it keeps it around outside the exec because SQL Server can reuse the proc's query plan.
The proc disappears as soon as the session where it was defined (via the exec) is closed.
MS is very careful indicate that temp 'tables' (one with one # sign) are local to the context and not visible to calling program.
See:
Any tables you create are visible to the EXEC() context in
https://technet.microsoft.com/en-us/library/aa175921%28v=sql.80%29.aspx
Specifically, can I do this?
CREATE PROC AutoDestructiveStoredProcedure
AS
DROP PROC AutoDestructiveStoredProcedure
PRINT 'Still alive.'
GO
Is it a bad practice?
What is the expected behavior? Does it change based on implementation?
What would be the difference between executing this in SQL Server, MySQL and Oracle?
Yes, this will work -- at least in SQL Server 2008 R2. It continues executing until the end of the procedure and after that the procedure is gone.
Is it bad practice? I think so. In my mind, the main reason is that it mixes DDL with DML, imposing unexpected side effects on what is normally a well-understood operation (calling a stored procedure).
Unfortunately, I can't answer your question with respect to how it works on MySQL or Oracle.
Yes you can do this not sure why you would want to
CREATE PROC AutoDestructiveStoredProcedure
AS
PRINT 'Being killed'
DROP PROC AutoDestructiveStoredProcedure
PRINT 'Still alive.'
exec createAutoDestruct
print 'Alive Again'
GO
create proc createAutoDestruct as
Exec sp_executesql N'CREATE PROC AutoDestructiveStoredProcedure
AS
PRINT ''Being killed''
DROP PROC AutoDestructiveStoredProcedure
PRINT ''Still alive.''
exec createAutoDestruct
print ''Alive Again'' '
GO
AutoDestructiveStoredProcedure
AutoDestructiveStoredProcedure
I've gathered the following experimental evidence in Oracle. I created the following procedure:
create procedure selfdestruct is
begin
execute immediate 'drop procedure selfdestruct';
end selfdestruct;
Then, ran it using
exec selfdestruct;
The result appears to be a never-ending procedure. A brief look at the database activity reveals that the session is waiting on library cache pin, which appears to be the method that Oracle uses to prevent an procedural object from changing while it is in-use.
In brief, for Oracle, the answer is "No, you can't drop a procedure while it is running."
The reason is simple: I work on a database of which I am not the administrator and I do not want other people to see and edit my SP, so I create it at runtime from the program before running it and at the end I have to delete it in order not to leave it in the database.
you could use the self destruct to not forget objects on customers base
this will work in Microsoft SQL Server 2008 R2 (SP2) and on Oracle 11G(probaly 10g too)
on Microsoft SQL Server 2008 R2 (SP2)
CREATE PROC AutoDestructiveStoredProcedure
AS
PRINT 'Being killed'
DROP PROC AutoDestructiveStoredProcedure
PRINT 'Still alive.'
print 'Alive Again'
GO
select OBJECT_ID('AutoDestructiveStoredProcedure')
--1243151474
exec AutoDestructiveStoredProcedure
--Being killed
--Still alive.
--Alive Again
select OBJECT_ID('AutoDestructiveStoredProcedure')
--null
On oracle
SET serveroutput ON size unlimited;
CREATE OR REPLACE PROCEDURE selfdestruct
AS
v_plSqlBlock varchar2(500);
v_job_int binary_integer;
BEGIN
DBMS_OUTPUT.PUT_LINE('Being killed');
v_plSqlBlock :='
BEGIN
execute immediate ''drop procedure selfdestruct'';
END;
';
dbms_job.submit(
job => v_job_int,
what => v_plSqlBlock
);
commit;
DBMS_OUTPUT.PUT_LINE('Still alive.');
DBMS_OUTPUT.PUT_LINE('Alive Again');
END selfdestruct;
/
SELECT count(1)
FROM dba_procedures
WHERE object_name = upper('selfdestruct');
I'm trying to execute a stored procedure directly after its creation however it is not getting called. It looks like the stored procedure is not yet created during the execution call.
Here is how the script looks like:
CREATE PROCEDURE sp_Transfer_RegionData
AS
BEGIN
INSERT INTO Region (regionName)
SELECT column1
FROM openquery(ITDB, 'select * from db.table1')
END
EXEC sp_Transfer_RegionData
The script runs fine however the needed table is not populated. After replacing the execution part with:
IF OBJECT_ID('sp_Transfer_RegionData') IS NOT NULL
begin
exec [dbo].[sp_Transfer_RegionData]
print 'tada'
end
I could see that the stored procedure does not exist when it has to be executed. Couldn't find a solution for this in the internet...
So how to make the SQL script run sync so that the stored procedure would already exist during the execution part?
You need a GO after you created the SP otherwise you have created a recursive SP that calls itself "indefinitely" which is 32 times in SQL Server.
Maximum stored procedure, function, trigger, or view nesting level
exceeded (limit 32).
Try this:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE sp_Transfer_RegionData
AS
BEGIN
INSERT INTO Region (regionName)
SELECT column1
FROM openquery(ITDB, 'select * from db.table1')
END
GO
EXEC sp_Transfer_RegionData
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
Create PROCEDURE [dbo].[SD_Sproc_Insurance_Insert]
-- Add the parameters for the stored procedure here
(
#HCSInsuranceID bigint,
#HCSInsuranceCode varchar(10),
#HCSInsuranceName varchar(100),
#IsPPS bit,
#IsActive bit
)
AS
BEGIN TRAN InsuranceInsert
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
INSERT INTO SD_Sproc_ToGRS_Insurance(HCSInsuranceID ,HCSInsuranceCode, HCSInsuranceName, IsPPS ,IsActive)
VALUES (#HCSInsuranceID ,#HCSInsuranceCode, #HCSInsuranceName, #IsPPS, #IsActive);
COMMIT TRAN InsuranceInsert
The SD_Sproc_ToGRS_Insurance is the stored that I'll call.. I'm having a problem to call this one. Anyone suggest? That I'm doing the right path to call a stored procedure?
The above is SQL Server syntax. Use the exec command like so to call a stored procedure.
exec storedProcName #param1Name, #param2Name
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?
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.
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.
Update:
In SQL Server 2016+, you can just do
CREATE OR ALTER PROCEDURE dbo.MyProc
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 know you want to "ALTER a procedure if it exists and create it if it does not exist", but I believe it is simpler to:
Drop the procedure (if it already exists) and then
Re-create it.
Like this:
IF OBJECT_ID('MyProcedure', 'P') IS NOT NULL
DROP PROCEDURE MyProcedure
GO
CREATE PROCEDURE MyProcedure AS
BEGIN
/* ..... */
END
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
TR = Trigger
You can get the full list of options via:
SELECT name
FROM master..spt_values
WHERE type = 'O9T'
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
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
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]
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:
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
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 ...
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 ...
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
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')
**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
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
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
..........
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.
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!
CREATE Procedure IF NOT EXISTS 'Your proc-name' () BEGIN ... END