public function join($type, $resource, $condition)
    {
        settype($condition, 'array');

        if (strpos($resource, $this->_prefix) !== 0) {
            $resource = $this->_prefix.$resource;
        }

        $this->join[] = array(
            'type' => strtoupper($type),
            'resource' => $resource,
            'condition' => $condition,
        );

        return $this;
    }