protected function processJSONForeignKeys($file)
    {
        $json = File::get($file);
        $fields = json_decode($json);

        if (! property_exists($fields, 'foreign_keys')) {
            return '';
        }

        $foreignKeysString = '';
        foreach ($fields->foreign_keys as $foreign_key) {
            $foreignKeysString .= $foreign_key->column . '#' . $foreign_key->references . '#' . $foreign_key->on;

            if (property_exists($foreign_key, 'onDelete')) {
                $foreignKeysString .= '#' . $foreign_key->onDelete;
            }

            if (property_exists($foreign_key, 'onUpdate')) {
                $foreignKeysString .= '#' . $foreign_key->onUpdate;
            }

            $foreignKeysString .= ',';
        }

        $foreignKeysString = rtrim($foreignKeysString, ',');

        return $foreignKeysString;
    }