Why PDO generates warnings when we tell it not to do it?

Question

Problem

We tell PDO to wrap each issue into exception. In some cases it generates a few warnings and only then throws exception.

Why

Answer 1

Use set_error_handler() and restore_error_handler()

public function query($sql)
{
    $retries = 0;
    $result = null;

    while (true) {
        try {
            set_error_handler(function () {
            });
            $result = $this->pdo->query($sql);
            restore_error_handler();
            break;
        } catch (Exception $e) {
            restore_error_handler();
            if (++$retries < self::RECONNECT_ATTEMPT) {
                if (strpos($e->getMessage(), 'server has gone away') !== false) {
                    $this->connect();
                    $this->getLogger()->info('Reconnect database, reason: server has gone away');
                }
            } else {
                throw $e;
            }
        }
    }
    return $result;
}