protected function parameters()
    {
        $index = 0;
        $parameters = [
            'p' => [],
            'c' => []
        ];

        foreach ($this->properties as $name => $property) {
            if ($name !== $this->primary && false === isset($property['column'])) {
                $index++;

                $parameters['p'][$index] = $name . ' = ?';
                $parameters['c'][$index] = $name;
            }
        }

        return $parameters;
    }