[Catalyst] How safe are database transactions?

[Chisel Wright]

On Thu, Jan 04, 2007 at 11:11:10AM +0000, Ash Berlin wrote:
> $c->model('MyAppDB')->txn_do(sub {
>   # Do some insertions here....
> });

Yes, this is pretty much how I do it too, e.g.:

  sub _add_new_reply {
    my ($self, $c) = @_;
    my ($new_reply);

    # some checks

    # otherwise, the form data is ok ...
    else {
        # try to add the reply to the thread
        eval {
            $new_reply = $c->model('ParleyDB')->schema->txn_do(
                sub { return $self->_txn_add_new_reply($c) }
            );
        };
        # deal with any transaction errors
        if ($@) {                                   # Transaction failed
            die "something terrible has happened!"  #
                if ($@ =~ /Rollback failed/);       # Rollback failed

            $c->stash->{error}{message} =
                qq{Database transaction failed: $@};
            $c->log->error( $@ );
            return;
        }
    }
  }
[source: http://xrl.us/t4w3]

and then all the db manipulation goes into "sub _txn_add_new_reply{...}"

I think this is pretty much how the docs recommend to do it. I've not
yet thought of a cleaner way to do this.

Chiz
-- 
Chisel Wright
e: chisel at herlpacker.co.uk
w: http://www.herlpacker.co.uk/

  Q: What's tiny and yellow and very, very, dangerous?
  A: A canary with the super-user password.