Retrieving records with _____________ relationship? - php

Question

I have 5 tables.
User tabel => This table stores the data of users.
Exam table => This table stores the data of exams.
Feeds table => This table stores the data of feeds.
Exam_User_Pivot table => This table stores the data of users and exams means the user_id and exam_id.
Exam_Feed_Pivot table => This table stores the data of exams and feeds means the exam_id and feed_id.
Now, I want to retrieve the no. of users per each feed ?
I have three models :
1. User Model
<?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. Exam Model
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class exam extends Model
{
protected $primaryKey = 'eid';
protected $fillable = [
'exam_name',
];
}
3. Feed Model
<?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();
}
}
Users have many-to-many relationship with Exams
Feeds have many-to-many relationship with Exams
I want to retrieve the no. of users per each feed And I don't know which relationship can be use ?

Answer 1

So first add the following two functions to your Exam Model.
Add to Exam model:
public function feeds() {
return $this->belongsToMany('App\Feed')->withTimeStamps(); //
}
public function users() {
return $this->belongsToMany('App\User')->withTimeStamps(); //
}
I want to retrieve the no. of users per each feed .....
The reasoning is based on the following three points:
get the feed,
then get exams of that feed (one feed has many exams)
then get users in each of these exams (here we will use a loop to ensure we count users of each exam from 2 above)
Loop through all feeds as:
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";
}
Expected output will be as follows ...
Feed myfeed has 10 users
Feed otherfeed has 38 users
Now to test it, just go to your routes/web.php and add the following code
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";
}
});
then open your browser and type this link:
http://YOUR_PROJECT_NAME_HERE/getusers and press enter:
Note: Replace YOUR_PROJECT_NAME_HERE with your actual project name. Make sure you have some exams,users, and feeds already in your database.
MY RESULTS

Answer 2

/**
* 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();
}