Question

我有一个发送群组电子邮件的功能，但我需要访问特定群组的联系人列表。我试过EagerLoading和链接，但似乎无法让它工作。所以在sendCommunications()函数中，这一行引起了我的问题：

$contacts = $message->group->contact()->select(array('email_address'));

我从命令行收到的错误消息是：

Call to undefined method Illuminate\\Database\\Eloquent\\Collection::contact()

这就是我到目前为止所做的：

控制器功能：

public static function sendCommunications()
{
    $queued_messages = QueuedMessage::with(array('message' => function($query)
    {
        $query->where('distribution_date_time', '<=', DB::raw('NOW()'));    
    }))->get();

    foreach ($queued_messages as $queued)
    {
        $message = $queued->message;
        $contacts = $message->group->contact()->select(array('email_address'));

        foreach ($contacts as $contact)
        {
            Message::send($message->email_title.'\n'.$message->email_body, $contact->email_address, $message->department->short_name);
        }
        $queued->delete();
    }
}

模型：

QueuedMessage：

class QueuedMessage extends Eloquent
{
    protected $primaryKey   = 'queued_message_pk';
    protected $table        = 'queued_messages';
    public $timestamps      = false;

    public function message()
    {
        return $this->belongsTo('Communication', 'message_fk');
    }
}

通信：

class Communication extends Eloquent
{
    protected $primaryKey   = 'message_pk';
    protected $table        = 'messages';
    public $timestamps      = false;        

    public function establishment()
    {
        return $this->belongsTo('Establishment', 'establishment_fk');
    }
    public function group()
    {
        return $this->belongsToMany('Group', 'messages_groups', 'message_fk', 'group_fk');
    }
}

组：

class Group extends Eloquent
{
    protected $primaryKey   = 'group_pk';
    protected $table        = 'groups';
    public $timestamps      = false;

    public function department()
    {
        return $this->belongsTo('Department', 'department_fk');
    }
    public function contact()
    {
        return $this->belongsToMany('Contact', 'contacts_groups', 'group_fk', 'contact_fk');
    }
    public function message()
    {
        return $this->belongsToMany('Communication', 'messages_groups', 'group_fk', 'message_fk');
    }       
}

与

class Contact extends Eloquent
{
    protected $primaryKey   = 'contact_pk';
    protected $table        = 'contacts';
    public $timestamps      = false;        

    public function department()
    {
        return $this->belongsTo('Department', 'department_fk');
    }
    public function group()
    {
        return $this->belongsToMany('Group', 'contacts_groups', 'contact_fk', 'group_fk');
    }
}

Answer 1

这是由于group()返回一个集合，即一组结果，而不是一个结果。

您无法对一组项目进行方法调用。

您可以循环浏览group中返回的项目，然后依次致电contact每个项目，ala

$contacts = array();
foreach($message->group as $group){
    merge_array($contacts, $group->contact()->select(array('email_address')));
}

Answer 2

如果您注意到您的Eloquent课程Communication，则会使用belongsToMany关系。当您致电$message->group时，这将返回Collection个小组。

你可以尝试

$message->group->each(function($group) use($message){
   $group->contact()->get('email_address')->each(function($contact) use($message){
          Message::send($message->email_title.'\n'.$message->email_body, $contact->email_address, $message->department->short_name);
   });
});

Eloquent Collection提供了一个each函数来遍历集合，该集合将回调作为参数来执行集合的附加操作。希望这有帮助

在Laravel中从另一个多对多关系中访问模型

2 个答案: