Laravel hasMany 关系不循环显示结果
声明:本页面是StackOverFlow热门问题的中英对照翻译,遵循CC BY-SA 4.0协议,如果您需要使用它,必须同样遵循CC BY-SA许可,注明原文地址和作者信息,同时你必须将它归于原作者(不是我):StackOverFlow
原文地址: http://stackoverflow.com/questions/23172367/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Laravel hasMany relationship not looping through to display results
提问by Jarek Tkaczyk
An alert can have many messages associated with it, through a foreign key. Each message sent is also attached to a user, through a foreign key. On viewing the alert, if such messages exist (they are not required), I want to display each message, along with the associated user's details.
通过外键,警报可以有许多与之相关的消息。发送的每条消息也通过外键附加到用户。在查看警报时,如果存在此类消息(它们不是必需的),我想显示每条消息以及相关用户的详细信息。
User model:
用户模型:
public function alerts()
{
return $this->hasMany('Alert');
}
public function messages()
{
return $this->hasMany('Message');
}
Alert model:
警报模型:
public function user()
{
return $this->belongsTo('User');
}
public function messages()
{
return $this->hasMany('Message');
}
I have noticed if the alert doesn't have any messages associated with it, the forloop
doesn't work!
我注意到如果警报没有任何与之关联的消息,则forloop
不起作用!
Within my show
view, I have:
在我show
看来,我有:
@foreach($alerts as $alert)
<tr>
<td>{{ $alerts->messages->first()->firstname }}</td>
<td>{{ $alerts->messages->first()->user->email }}</td>
<td>{{ $alerts->messages->first()->user->phone_number }}</td>
<td>{{ $alerts->messages->first()->message }}</td>
<td>{{ date("j F Y", strtotime($alerts->messages->first()->created_at)) }}</td>
<td>{{ date("g:ia", strtotime($alerts->messages->first()->created_at)) }}</td>
</tr>
@endforeach
Which works great, if there are messages to show, but it only loops through the first message, not the rest of them. The controller pulling in the data is:
如果有消息要显示,这很好用,但它只循环显示第一条消息,而不是其余消息。拉入数据的控制器是:
public function show($id)
{
$alert = Alert::where('id','=',$id)->first();
$this->layout->content = View::make('agents.alert.show',
array('alerts' => $alert));
}
Any guidance as to why the forloop
doesn't work when there is less 2 results, and why it only loops through the first result. Thank you.
关于为什么在forloop
少于 2 个结果时不起作用的任何指导,以及为什么它只循环遍历第一个结果。谢谢你。
回答by Jarek Tkaczyk
First I suggest using eager loading for related models or you will run many db queries that you don't want nor need:
首先,我建议对相关模型使用预先加载,否则您将运行许多您不需要也不需要的数据库查询:
public function show($id)
{
$alert = Alert::with('messages.user')->where('id','=',$id)->first();
$this->layout->content = View::make('agents.alert.show', array('alert' => $alert));
}
Then in you view spin through messages, not alerts as you don't have many of them:
然后在您查看旋转消息,而不是警报,因为您没有很多消息:
@foreach($alert->messages as $message)
<tr>
<td>{{ $message->firstname }}</td>
// if you are sure there is a user for each message, otherwise you need a check for null on $message->user
<td>{{ $message->user->email }}</td>
<td>{{ $message->user->phone_number }}</td>
<td>{{ $message->message }}</td>
<td>{{ date("j F Y", strtotime($message->created_at)) }}</td>
<td>{{ date("g:ia", strtotime($message->created_at)) }}</td>
</tr>
@endforeach