public function update_user_password($user, $host = '%', $password = null, $password_format_mysql = false) {
		if ($password == null) {
			$password = md5(mt_rand() . microtime());
		}

		if ($password_format_mysql) {
			$password = $this->quote($password);
		} else {
			$password = 'PASSWORD(' . $this->quote($password) . ')';
		}

		$query = 'SET PASSWORD FOR ' . $this->quote_identifier($user) . '@' . $this->quote($host) . ' = ' . $password;
		$statement = $this->get_statement($query);
		$statement->execute();

		$query = 'FLUSH PRIVILEGES';
		$statement = $this->get_statement($query);
		$statement->execute();
	}