How to work with client side transactions in VB.net for DB2 DSN

I have an application in VB.net that does inserts into three different tables. Insert into table 1 is done by DB2 stored procedure1. Insert into table 2 DEPENDS on the success of the insert into table 1 and is achieved by a DB stored procedure 2. Insert into table 3 depends on success of inserts into table2 [hence success of insert into table1] and is done with a DB2 stored procedure 3.

Now, when i am at the insert into table3 [assuming that inserts 1 and 2 have completed successfully] and the insert FAILS, I want to ROLLBACK the inserts into table 2 and inserts into table 1. Now, I cannot change the stored procedure because this is a 3 tier development architecture where the database objects are shielded from the "view" layer [this is not a WEB APP]. I have three methods that do these inserts.

I have heard of this "transaction scope" object in .net but I do not see a "rollback" option in there. So, my question is how would I go about coding the "rollback" transaction option to this scenario? More than the commit, I need the rollback.

App: Vb.net, database:DB2 on Z/os[mainframe]
VBSolutionSeekerAsked:
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Kent OlsenConnect With a Mentor Data Warehouse Architect / DBACommented:
Hi VBSolutionSeeker,

A transaction is a logical unit of work.  (Silly words right out of the 'manual'.)  Support for running in a transaction environment varies with the different clients and applications.

But I know of no way to maintain a transaction across multiple connections.  If your application connects, runs procedure1 and disconnects, then reconnects to run procedure2, the updates performed by procedure1 are already committed.  You can not roll them back.

Also, if the procedure does an explicit commit, you're in the same situation.  DB2 doesn't care where the commit is initiated.  A commit is a commit.

All that said, what you probably want is middleware that will maintain a connection to DB2 and allow your VB code to interact with it.  It's not necessarily cheap, and it will require a significant amount of recoding on your end.


Good Luck,
Kent
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ocgstylesConnect With a Mentor Commented:
Hi VBSolutionSeeker,

I agree with Kdo.

But if there's the slight chance you can combine the 3 stored procedures into 1, then you could just make it an atomic transaction.  When atomic, its all or none.  If SP2 failed, so does 1, if SP3 fails, so does 1 and 2.

But like you said, that's not an option...

Keith
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tliottaConnect With a Mentor Commented:
Minor question... does "cannot change the stored procedure" also mean that a new stored proc _cannot_ be created?

Tom
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