Php Laravel有许多关系无法访问该关系
控制器功能(应返回2个结果及其位置和消息计数): 用户模型:Php Laravel有许多关系无法访问该关系,php,laravel,foreach,laravel-4,Php,Laravel,Foreach,Laravel 4,控制器功能(应返回2个结果及其位置和消息计数): 用户模型: public function alerts() { return $this->hasMany('Alert'); } 警报模型: public function location() { return $this->belongsTo('Location'); } public function user() { ret
public function alerts()
{
return $this->hasMany('Alert');
}
警报模型:
public function location()
{
return $this->belongsTo('Location');
}
public function user()
{
return $this->belongsTo('User');
}
public function messages()
{
return $this->hasMany('Message');
}
查看:
@foreach($alerts as $alert)
<tr>
<td>{{ $alert->location->address_1}}</td>
<td>{{ $alert->location->address_2}}</td>
<td>{{ $alert->location->address_3}}</td>
<td>{{ $alert->location->postcode}}</td>
<td>{{ $alert->messages->count()}}</td>
</tr>
@endforeach
@foreach($alert作为$alert)
{{$alert->location->address_1}
{{$alert->location->address_2}
{{$alert->location->address_3}
{{$alert->location->postcode}
{{$alert->messages->count()}
@endforeach
尝试访问位置
或消息
的任何回显都会失败-
尝试获取非对象的属性时出错异常
我将查询从->first()方法更改为->get()方法,这就是问题的起因。每个警报肯定有多条消息和一个与之关联的位置。看起来$alerts是一个用户数组,您将其用作警报数组。 试试这个:
$alerts = User::with('alerts.location')
->where('id', '=', Auth::user()->id)->first()->alerts;
get()的问题在于,即使有0或1个结果,它也会返回一个数组,而您似乎只需要一个结果
$alerts = User::with('alerts.location')->where('id', '=', Auth::user()->id)->get();
上面这一行返回一个用户模型的雄辩集合,该模型具有急切加载的嵌套关系,但没有像您希望的那样发出警报,也没有在此处急切加载消息,因此您将在foreach循环中面临n+1问题。
另外,您已经在Auth::user()中加载了用户,所以无需再次查询users表
相反,请使用以下命令:
$alerts = Auth::user()->alerts // this loads all alerts as a Collection
->load('location') // here we eager load related Location for every Alert
->load('messages'); // and here we eager load related messages for all Alerts
// now $allerts is a Collection of Alert models and related Local models
// so this will work (Still add some check for ->location as it might be null
// if there is no related location for an alert):
@foreach($alerts as $alert)
<tr>
<td>{{ $alert->location->address_1 }}</td>
<td>{{ $alert->location->address_2 }}</td>
<td>{{ $alert->location->address_3 }}</td>
<td>{{ $alert->location->postcode }}</td>
<td>{{ $alert->messages->count() }}</td>
</tr>
@endforeach
$alerts=Auth::user()->alerts//这会将所有警报作为一个集合加载
->load('location')//这里我们为每个警报指定与加载相关的位置
->加载('消息');//在这里,我们为所有警报加载相关消息
//现在$allerts是警报模型和相关本地模型的集合
//因此,这将起作用(仍然添加一些检查->位置,因为它可能为空)
//如果没有警报的相关位置):
@foreach($alert作为$alert)
{{$alert->location->address_1}
{{$alert->location->address_2}
{{$alert->location->address_3}
{{$alert->location->postcode}
{{$alert->messages->count()}
@endforeach
$alerts = Auth::user()->alerts // this loads all alerts as a Collection
->load('location') // here we eager load related Location for every Alert
->load('messages'); // and here we eager load related messages for all Alerts
// now $allerts is a Collection of Alert models and related Local models
// so this will work (Still add some check for ->location as it might be null
// if there is no related location for an alert):
@foreach($alerts as $alert)
<tr>
<td>{{ $alert->location->address_1 }}</td>
<td>{{ $alert->location->address_2 }}</td>
<td>{{ $alert->location->address_3 }}</td>
<td>{{ $alert->location->postcode }}</td>
<td>{{ $alert->messages->count() }}</td>
</tr>
@endforeach