模型功能返回空的一列

Question

主要照片

我创建了发送到控制器ID的更新表单，并且一切正常。但是，主要照片我如何检查返回首先添加的数据。例如，event_id = 2没有主图像，event_id = 4具有main_photo（例如：test），但它获取event_id = 2空值。我花了很多时间找不到解决方案。

Modell

public function get_list_for_edit($event_id){
    return
    $this->db->select('*')
              ->select('pn.title as push_title, e.title as event_title', false) 
              ->from('events e')
              ->join('events_locations el','el.event_id =' . $event_id,'left')
              ->join('push_notifications pn',
                      'pn.type_id ='. $event_id,'left')
              ->get('events')
              ->row_object();
}

数组1 event_id = 2

  stdClass Object
   (
[event_id] => 2
[title] => test1 -pushnotificationtitle
[description] => <p>Test1 -description</p>
[main_photo] => 
[start] => 2017-03-12 08:00:00
[end] => 2017-03-15 06:00:00
[phone] => 946871783
[email] => [e-mail]
[keywords] => test1 -keywords
[created_at] => 2017-03-12 20:29:09
[status] => active
[deleted] => 0
[event_location_id] => 2
[country_id] => 1
[city_id] => 1
[area_id] => 1
[street] => Tinchlik street
[building_no] => Tinchlik street
[latitude] => 25.218670435768225
[longitude] => 55.29264020500705
[push_notificaion_id] => 2
[type] => event
[type_id] => 2
[datetime] => 2017-03-12 20:29:09
[message] => test1 -pushnotificationmessage
[push_title] => test1 -pushnotificationtitle
[event_title] => Test1
 )

数组2 event_id = 5

stdClass Object
 (
[event_id] => 5
[title] => test4 - notificationtitle
[description] => <p>Test1 -description</p>
[main_photo] => 
[start] => 2017-03-12 08:00:00
[end] => 2017-03-15 06:00:00
[phone] => 946871783
[email] => [e-mail]
[keywords] => test1 -keywords
[created_at] => 2017-03-12 20:45:47
[status] => active
[deleted] => 0
[event_location_id] => 5
[country_id] => 1
[city_id] => 1
[area_id] => 1
[street] => Tinchlik street
[building_no] => Tinchlik street
[latitude] => 25.197858466144194
[longitude] => 55.244231696706265
[push_notificaion_id] => 5
[type] => 
[type_id] => 5
[datetime] => 2017-03-17 08:00:00
[message] => test4 - notificationtitle
[push_title] => test4 - notificationtitle
[event_title] => Test1
  )

Answer 1

如果我正确理解并且需要获取一个图像，但是主要图像可能会或可能不可用，这就是我要做的：

控制器：

//get your event
$data['event'] = $this->db->get_where('event_table')->row();
$data['event']->main_image = $this->event_model->get_main_image($data['event']);

模型：

        //get all images
        $images = $this->db->get_where('e_products_main_images', array('main_image_product_id_fk' => $product->product_id))->result();
        $image = null;
        //check if main exists
        foreach ($images as $key => $animage) {
            if ($aniamge->is_main == '1') {
                $image = $aniamge;
            } 
        }
        //if not get the first one
        if ($image == null and isset($images[0])) {
            $image = $images[0];
        }
        //or return null
        if ($image == null) {
            return null;
        }
        return $image->main_image_path;