问题描述
我正在使用Laravel 5.0开发Web API,但不确定要构建的特定查询.
I'm developing a web API with Laravel 5.0 but I'm not sure about a specific query I'm trying to build.
我的课程如下:
class Event extends Model {
protected $table = 'events';
public $timestamps = false;
public function participants()
{
return $this->hasMany('App\Participant', 'IDEvent', 'ID');
}
public function owner()
{
return $this->hasOne('App\User', 'ID', 'IDOwner');
}
}
和
class Participant extends Model {
protected $table = 'participants';
public $timestamps = false;
public function user()
{
return $this->belongTo('App\User', 'IDUser', 'ID');
}
public function event()
{
return $this->belongTo('App\Event', 'IDEvent', 'ID');
}
}
现在,我想让特定参与者参加所有活动.我尝试过:
Now, I want to get all the events with a specific participant.I tried with:
Event::with('participants')->where('IDUser', 1)->get();
,但where
条件适用于Event
而不是其Participants
.以下是我的例外情况:
but the where
condition is applied on the Event
and not on its Participants
. The following gives me an exception:
Participant::where('IDUser', 1)->event()->get();
我知道我可以这样写:
$list = Participant::where('IDUser', 1)->get();
for($item in $list) {
$event = $item->event;
// ... other code ...
}
但是向服务器发送这么多查询似乎不是很有效.
but it doesn't seem very efficient to send so many queries to the server.
使用Laravel 5和Eloquent通过模型关系执行where
的最佳方法是什么?
What is the best way to perform a where
through a model relationship using Laravel 5 and Eloquent?
推荐答案
在您的关系中执行此操作的正确语法是:
The correct syntax to do this on your relations is:
Event::whereHas('participants', function ($query) {
return $query->where('IDUser', '=', 1);
})->get();
更多信息,请参见 https://laravel.com/docs/5.8/eloquent -relationships#eager-loading
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