RE: Committing rolling back many objects at once?

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thank you very much. This looks great. i  tried that a while back and found
that it would only rollback the last object created.  But i may have done it
wrong. I'm glad to hear you can rollback many objects.  I'll try again. 

--- "Addison, Mark" <Mark.Addison@xxx.xx.xx> wrote:

> From: Peter Speltz Sent: 20 January 2005 18:15
> <snip>
> > That's a quick response :). thanks.  Ok. so I CAN create many 
> > and commit many
> > at once or rollback many at once but just not individually. 
> > very cool. So to
> > update my example : this should work:
> > 
> > my $person = Person->create( ...);
> > my $emp    = Employee->create(...);
> > if ($error) {
> >    MyModelBase->dbi_rollback;
> > }
> > else {
> >    MyModelBase->dbi_commit;
> > }
> > 
> > That's very cool if that works. thanks
> 
> A very nice way to handle transactions is Dominic Mitchell's
> do_transaction method which you will find in the CDBI docs (also
> I've copied it in below). Once you have that in you base class
> you would do:
> 
>  my ($person,$emp);
>  MyModuleBase->do_transaction( sub {
>      $person = Person->create( ...);
>      $emp    = Employee->create(...); 	
>  });
> 
> It does error trapping for you and automatically rolls back
> if anthing fails (and re-throws the exception) or commits 
> otherwise. 
> The other thing I've found is it helps you keep the scope of
> your transactions small and all in one place. Which is 
> (nearly) always a good idea!
> 
>         sub do_transaction {
>                 my $class = shift;
>                 my ( $code ) = @_;
>                 # Turn off AutoCommit for this scope.
>                 # A commit will occur at the exit of this block
> automatically,
>                 # when the local AutoCommit goes out of scope.
>                 local $class->db_Main->{ AutoCommit };
> 
>                 # Execute the required code inside the transaction.
>                 eval { $code->() };
>                 if ( $@ ) {
>                         my $commit_error = $@;
>                         eval { $class->dbi_rollback }; # might also die!
>                         die $commit_error;
>                 }
>         }
> 
> mark
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=====
pjs


		
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