Create sql trigger dynamically and rollback if error - sql

Question

I'm creating a stored procedure that will create 3 triggers (insert, update, delete) given a table name.
Here is an example to illustrate the issue I'm experiencing :
CREATE PROCEDURE [dbo].[sp_test]
AS
BEGIN
BEGIN TRAN
-- Create trigger 1
DECLARE #sql NVARCHAR(MAX) = 'CREATE TRIGGER test1 ON TableXML AFTER INSERT AS BEGIN END'
EXEC sp_executesql #sql
-- Create trigger 2, but this one will fail because Table_1 contain an ntext field.
SET #sql = 'CREATE TRIGGER test1 ON Table_1 AFTER INSERT AS
BEGIN
select * from inserted
END'
EXEC sp_executesql #sql
COMMIT TRAN
END
So I thought that wrapping the call in a transaction, the first trigger won't be created. Since the second will fail. BUT the first trigger is created anyway .... How can I prevent this from happening. I want the whole thing to be atomics.

Answer 1

Try this, with BEGIN TRY
CREATE PROCEDURE [dbo].[sp_test]
AS
BEGIN
BEGIN TRY
BEGIN TRAN
DECLARE #sql NVARCHAR(MAX) = 'CREATE TRIGGER test1 ON TableXML AFTER INSERT AS BEGIN END'
EXEC sp_executesql #sql
SET #sql = 'CREATE TRIGGER test1 ON Table_1 AFTER INSERT AS
BEGIN
select * from inserted
END'
EXEC sp_executesql #sql
COMMIT TRAN
END TRY
BEGIN CATCH
RAISERROR('Errormessage', 18, 1)
ROLLBACK TRAN
END CATCH
END

Answer 2

You have no error handling or rollback statement in your procedure.

Answer 3

In some databases, DDL statements such as CREATE TRIGGER will automatically commit themselves; if sql-server is one of them, you can't. (This is true of Oracle and MySQL; not true of RDB; not sure about sql-server.)

Answer 4

You don't have a Rollback call on an error.
Using SQL Server's Try/Catch, you could do something like what Vidar mentioned, or you if Sql Server automatically commits triggers (as Brian H mentioned as a posibility) you could instead have in your Catch block:
BEGIN CATCH
RAISERROR('Errormessage', 18, 1)
DROP Trigger test1
END CATCH