What is the scope of TRANSACTION in Sql server
I was creating a stored procedure and I see some differences between my methodology and my colleague's.
I am using SQL Server 2005
My Stored procedure looks like this
BEGIN TRAN BEGIN TRY INSERT INTO Tags.tblTopic (Topic, TopicCode, Description) VALUES(@Topic, @TopicCode, @Description)
INSERT INTO Tags.tblSubjectTopic (SubjectId, TopicId) VALUES(@SubjectId, @@IDENTITY) COMMIT TRAN END TRY BEGIN CATCH DECLARE @Error VARCHAR(1000) SET @Error= 'ERROR NO : '+ERROR_NUMBER() + ', LINE NO : '+ ERROR_LINE() + ', ERROR MESSAGE : '+ERROR_MESSAGE() PRINT @Error ROLLBACK TRAN END CATCH
And my colleague's way of writing looks like the below one
BEGIN TRY BEGIN TRAN INSERT INTO Tags.tblTopic (Topic, TopicCode, Description) VALUES(@Topic, @TopicCode, @Description)
INSERT INTO Tags.tblSubjectTopic (SubjectId, TopicId) VALUES(@SubjectId, @@IDENTITY) COMMIT TRAN END TRY BEGIN CATCH DECLARE @Error VARCHAR(1000) SET @Error= 'ERROR NO : '+ERROR_NUMBER() + ', LINE NO : '+ ERROR_LINE开发者_如何学Go() + ', ERROR MESSAGE : '+ERROR_MESSAGE() PRINT @Error ROLLBACK TRAN END CATCH
Here the only difference between the two methods is the position of Begin TRAN
.
According to me my colleague's method should not work when an exception occurs i.e. Rollback
should not get executed because TRAN doesn't have scope in method 2. But when I tried to run both the methods, they were working in the same way.
In Method 1, scope of TRAN is outside of try block so it should be visible in both try block and catch block and should give result as per the scope methodology of programming works.
In Method 2, scope of TRAN is limited within Try block so Commit
and Rollback
should occur within the try block and should throw exception when a Rollback
with no Begin Tran
exists in catch block, but this is also working perfectly.
I am confused about how TRANSACTION works. Is it scope-free?
Transactions are not "scoped" in the way that programming languages are.
Transactions are nested for the current connection. Each BEGIN TRAN starts a new transaction and this transaction ends whenever a COMMIT or ROLLBACK is called, it does not matter where in your stored proc this is.
Transactions are nested for the current connection. Each BEGIN TRAN starts a new transaction and this transaction ends whenever a COMMIT or ROLLBACK is called, it does not matter where in your stored proc this is.
only to add that ROLLBACK ends "all" open transactions for the connection...
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