Re: transactions, row locking, race condition?

From: Tore Halset (halse..vv.ntnu.no)
Date: Mon Apr 11 2005 - 09:10:14 EDT

  • Next message: Gentry, Michael \(Contractor\): "RE: transactions, row locking, race condition?"

    On Apr 11, 2005, at 15:05, Tore Halset wrote:

    > Using optimistic locking cayenne will create a sql update statement
    > like:
    > update candidates set my_timestamp='2005-04-11' where id=17 and
    > my_timestamp is null;

    Sorry, I was a bit short here.. If that sql does not update any rows a
    OptimisticLockException should be thrown.
    http://www.objectstyle.org/cayenne/api/cayenne/org/objectstyle/cayenne/
    access/OptimisticLockException.html

      - Tore.

    > "my_timestamp is null" is caused by the optimistic locking and is used
    > to make sure the row has not been modifyed by another client.
    >
    > http://www.objectstyle.org/confluence/display/CAY/
    > Optimistic+Locking+Explained

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