[Dbix-class] Problem with populate() and commits?

Chris Cole chris at compbio.dundee.ac.uk
Mon May 18 08:34:49 GMT 2009


Louis Erickson wrote:
> On Thu, 14 May 2009, Chris Cole wrote:
> 
> <snip>
> 
>> Why does it work fine when I have Autocommit 'on', but get the following
>> error with Autocommit 'off':
> 
> I'm surprised no one else has replied.  This bit me too when I first 
> started with DBIC.  It seemed backwards to me at the time.
> 
> DBIx::Class assumes autocommit is on, and works strangely or not at all if 
> it is off.
> 
> If you must have it off, say, to share a db handle with older code that 
> requires it, you can usually finesse it to work but transactions will be 
> hard. The one time I found myself in that situation, I discovered opening 
> a second handle was easier.
> 
> You'll be best off with DBIC to leave autocommit on and use DBIC's 
> transaction handling through txn_do instead.  It works well and handles 
> some things the raw DBI one won't.
> 
> The DBIx::Class::Storage::DBI documentation 
> (http://search.cpan.org/~ribasushi/DBIx-Class-0.08102/lib/DBIx/Class/Storage/DBI.pm#DBIx::Class_and_AutoCommit) 
> explains this:

Useful link. Thanks.

>> DBIx::Class and AutoCommit
>>
>> DBIx::Class can do some wonderful magic with handling exceptions, 
>> disconnections, and transactions when you use AutoCommit => 1 combined 
>> with txn_do for transaction support.
>>
>> If you set AutoCommit => 0 in your connect info, then you are always in 
>> an assumed transaction between commits, and you're telling us you'd like 
>> to manage that manually. A lot of the magic protections offered by this 
>> module will go away. We can't protect you from exceptions due to 
>> database disconnects because we don't know anything about how to restart 
>> your transactions. You're on your own for handling all sorts of 
>> exceptional cases if you choose the AutoCommit => 0 path, just as you 
>> would be with raw DBI.
> 
> Hope that explains it.  =)

Very much so. Thanks.




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