我有五张桌子。
用户标签=
现在，我想检索每个提要的用户数？
我有三种型号：
1.用户模型
<?php
namespace App;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
class User extends Authenticatable implements MustVerifyEmail
{
use Notifiable;
protected $primaryKey = 'uid';
/**
* The attributes that are mass assignable.
*
* @var array
*/
protected $fillable = [
'name', 'email', 'password', 'phone',
];
/**
* The attributes that should be hidden for arrays.
*
* @var array
*/
protected $hidden = [
'password', 'remember_token',
];
/**
* The attributes that should be cast to native types.
*
* @var array
*/
protected $casts = [
'email_verified_at' => 'datetime',
];
public function exams()
{
return $this->belongsToMany(exam::class, 'exam_user', 'user_id', 'exam_id')->withTimeStamps();
}
}
2.考试模式
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class exam extends Model
{
protected $primaryKey = 'eid';
protected $fillable = [
'exam_name',
];
}
3.饲料模型
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Feed extends Model
{
protected $primaryKey = 'fid';
protected $fillable = [
'feed_type', 'title', 'description', 'feed_media', 'source',
];
public function feedexams()
{
return $this->belongsToMany(exam::class, 'exam_feed', 'feed_id', 'exam_id')->withTimeStamps();
}
}
我想检索每个提要的用户数，我不知道可以使用哪种关系？
因此，首先将以下两个函数添加到您的考试模型中。
添加到考试模型：
public function feeds() {
return $this->belongsToMany('App\Feed')->withTimeStamps(); //
}
public function users() {
return $this->belongsToMany('App\User')->withTimeStamps(); //
}
我想检索每个提要的用户数......
推理基于以下三点：
将所有提要循环为：
foreach(App\Feed::all() as $feed) {
//here you are accessing all related exams using the function feedexams() that you have created in the feeds model
$exams = $feed->feedexams();
//because each exam will have its own users, we need a way to count the users for each exam, and finally ensure we sum or count all of them. we create a counter called $user_per_feed_count to keep or remember the users count as we loop through all exams.
//Finally we will output this counter which will have the total of all users belonging to exams which belong to the feed.
$users_count = 0; //initialize a users counter with zero
foreach($exams as $exam) {
//now we update our counter by adding the number of users for each exam
$users_count += $exam->users()->count();
}
//HERE IS YOUR no. of users per each feed.
echo "Feed " . $feed->name . "has " . $users_count . " users";
}
预期产出如下...
Feed myfeed有10个用户
Feed-otherfeed有38个用户
现在要测试它，只需转到您的routes/web。并添加以下代码
Route::get('getusers', function () {
foreach (App\Feed::all() as $feed) {
$exams = $feed->feedexams();
$users_count = 0; //initialize a users counter with zero
foreach ($exams as $exam) {
//$users_count += $exam->users()->count();
$users_count += $exam->has('users') ? $exam->users()->count() : 0;
}
echo "Feed " . $feed->name . "has " . $users_count . " users";
}
});
然后打开浏览器并键入以下链接：
http://YOUR_PROJECT_NAME_HERE/getusers然后按enter键：
注意：用实际项目名称替换此处的项目名称。确保数据库中已有一些考试、用户和提要。我的结果
/**
* Get all of the user for the feed. define in Feed Model
*/
public function feedUsers()
{
return $this->hasManyThrough(App\Models\Exam::class App\Models\User::class);
}
$feeds = App\Feed::all();
foreach($feeds as $feed){
echo $feed->feedUsers->count();
}
