How do transactions work in Wordpress?

Question

WordPress

Good afternoon everyone, how to work with transactions in Wordpress, I use the following code, attention - the commit is commented out:

try {
    $wpdb->query('START TRANSACTION');
    $result = $wpdb->query('TRUNCATE TABLE wp_competition_history');
    if (!$result) {
       throw new Exception("Ошибка БД");
    }
    //$wpdb->query('COMMIT');
} catch (Exception $ex) {
        $wpdb->query('ROLLBACK');
    }

In this example, the commit was not supposed to work, yet it does work as if the transactions weren't working. Tell me, please, how to do it right?

Answer 1

It's not clear whether you defined global $wpdb somewhere earlier;
Try replacing the condition with this

if (false === $result) {
throw new Exception("Ошибка БД. ".$wpdb->last_error);
}

I think it's a matter of conditions.