On 2024-09-08, Greg Ewing <greg.ew...@canterbury.ac.nz> wrote: > On 8/09/24 9:20 am, Karsten Hilbert wrote: >> try: >> do something >> except: >> log something >> finally: >> .commit() >> >> cadence is fairly Pythonic and elegant in that it ensures the >> the .commit() will always be reached regardless of exceptions >> being thrown or not and them being handled or not. > > That seems wrong to me. I would have thought the commit should only > be attempted if everything went right. > > What if there's a problem in your code that causes a non-SQL-related > exception when some but not all of the SQL statements in the > transaction bave been issued? The database doesn't know something > has gone wrong, so it will happily commit a partially-completed > transaction and possibly corrupt your data. > > This is how I normally do things like this: > > try: > do something > .commit() > except: > log something > .rollback() > > Doing an explicit rollback ensures that the transaction is always > rolled back if it is interrupted for any reason.
What if there's an exception in your exception handler? I'd put the rollback in the 'finally' handler, so it's always called. If you've already called 'commit' then the rollback does nothing of course. -- https://mail.python.org/mailman/listinfo/python-list
