[Dbix-class] ROLLBACK seems to be skipped on 0.08

[Brandon Black]

On 10/20/07, Jesper Krogh <jesper at krogh.cc> wrote:
> Brandon Black wrote:
> > What AutoCommit => 1 does is make it so that if you aren't in an
> > explicit transaction at the DBI (or DBIC) level, every statement is
> > committed as an individual transaction.  It doesn't prevent you from
> > using multi-statement transactions.  AutoCommit => 1 is generally
> > better all around, regardless of DBIC (but especially with DBIC), for
> > a lot of obvious (and a few non-obvious) reasons.
>
> I feel "safer" with manually controlling the transactions. I may just
> need to get to work with txn_do() so I can adjust my feelings :-)
>
> I had a "nice" feeling using AutoCommit => 0, knowing that stuff ONLY
> got into the database if I actually wanted it to.
>
> I've been writing a lot of "DB-fix"-scripts which I intentinally ran with:
> $schema->txn_begin;
> A lot of fixup.
> $schema->txn_rollback;
>

Or you can turn on AutoCommit, and make all your blocks:

$schema->txn_do(sub {
# a lot of fixup
});

> Running it alot of times during development.. knowing that the script
> first had an effect on data when I changed the last line. This is an
> extremely strong feature).
>
> I'd like to get rid of the implicit transaction.
>
> >> (I'll test Brandons suggestion tonight)
> >
> > The suggestion to comment out begin_work in your example is just to
> > test a theory about what our AutoCommit => 0 bug is.  I wouldn't
> > recommend leaving the code that way, as a future update will probably
> > break you when we fix this.  Even given all of the above, we haven't
> > actually made the leap of just forcing everyone to use AutoCommit =>
> > 1, so we'd still like to fix the bug :)
>
> Commenting out the txn_begin "solves" the problem.
>

Good :)

> > I'm leaning towards what I said earlier: requiring AutoCommit => 0
> > people to explicitly start their transactions before doing any work
> > (txn_begin or txn_do), and basically dropping support for AutoCommit
> > => 0 and implicit txn starts.
>
> That sounds reasonable to me.
>

I'll work out a patch for this sometime this weekend, we'll see on IRC
where it should go, as far as who it breaks, etc.

-- Brandon