Re: How to safely test if a database handle is capable of transactions?

[fmerges]

Hi,

While it's not breaking encapsulation, as Limbic~Region corrected, using 'begin_work' is the recommended way, as you get blamed by the driver if it's not supported

eval {
    $dbh->begin_work;
    # ...
    $dbh->commit;
};
if ($@) {
    $dbh->rollback;
    # If you want to be paranoid, check if it rolled back.
    # Look at manual: man DBI
}

Hope this helps you a bit

Regards,

Update: corrected about the encapsulation, thanks Limbic~Region

[Limbic~Region]

fmerges,
Where is encapsulation being broken?

$dbh->{AutoCommit} = 0;

The DBI is a tied interface and you are not really breaking encapsulation by doing this. This is a perfectly acceptable way of doing business with this module - just see the docs.

You did indirectly answer the OP's question (begin_work). According to the docs - If the driver does not support transactions then when begin_work attempts to set AutoCommit off the driver will trigger a fatal error. You just need to work it a bit differently since the OP wants to know if transactions are supported prior to trying a transaction. This means checking the actual contents of $@ rather than just seeing if it is set.

[ikegami]

The driver will die (or return an error if RaiseError => 0) whichever interface you use if transactions aren't unsupported.