is it possible (how) to use mysql transactions and rollbacks using kohana ORM ?
Check out the official forums. It shows an example on how to use transactions with Ko3:
$db->query(NULL, 'TRANSACTION START');
// Do stuff
$db->query(NULL, 'COMMIT');
How to do it with version 2, I don't know. I'm still new to kohana myself, and learning Ko3 rather than 2. But I'm guessing it's quite similar.
SQL Transactions in Kohana 3.x are not done the same way as in 2.x. In 3.x, the database class comes with transaction methods:
$db->begin();
$db->commit();
$db->rollback();
This also works if you are using ORM stuff. Just initiate the transaction before ORM saves, updates, a or deletes.
Read more in this post: http://dev.strategystar.net/2011/10/sql-transactions-with-kohana-3-x/
In 2.x, transactions had to be done manually:
$this->db->query("START TRANSACTION")
I've created a Kohana module that makes using transactions a lot easier:
https://github.com/brazzy/kohana-transactional
It does, however, require at least Kohana 3.1. But then you just add
public $_transactional = true;
to the controller, and all actions are automatically executed inside a transaction, which is rolled back when the action fails with an exception.