Laravel 5.2如何通过laravel雄辩的模型连接三个表

Question

I have three model

1. user 
2. course 
3. fee

where user model is connected with course table with one to many relationship and course model is connected with fees table with one to one relationship.

the problem is, I have to find sum of all fee's where user selected the course and there user's completed stauts should be 1. how to write the query for it?

Course Model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Course extends Model
{
    protected $table='courses';
    protected $fillable = ['name','date','publication_status'];


    public function fee(){
        return $this->hasOne('App\Fee','course_id', 'id');
    }
      public function user()
    {
        return $this->belongsToMany('App\User','course_id','id');
    }
}

User Model:

<?php

namespace App;

use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    protected $table='users';
     protected $fillable=['name','email','phone','course_id'];



          public function courses()
    {
        return $this->hasMany('App\Course','id','course_id');
    }
}

fee Model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Fee extends Model
{
        protected $table='fees';
    protected $fillable = ['fee','course_id'];

    public function course()
    {
        return $this->belongsTo('App\Course', 'course_id', 'id');
    }
}

if anybody know the solutions, please provide one.

Answer 1

I guess you can find the user first:

if(User::find($id)->complete_status == 1){
    $user = User::find($id);
}

After this you will return all courses of this user:

$courses = $user->courses;

And finally you'll implement a foreach statement to return each courses fee:

foreach($courses as $course){
    $feeSum += $course->fee->value;
}

A example to pass your fee sum to view:

return view('view_path' , compact('feeSum'));

Suposing that $feeSum is in the same function that return view statement.

After return the variable, in your view file you'll add this for example:

<label>{{ $feeSum }}</label>

Answer 2

You might want to look into using pivot-like relationships.

Your User model could have something like:

# Get the fees for a user:
public function fees()
{
    return $this->hasMany('App\Fees', 'fees', 'courses', 'course_id', 'course_id')
                ->withPivot('iterate', 'fields', 'here', 'to', 'pass', 'on')
                ->withTimestamps();
}

The code above has not been tested at all, but I'm pretty sure the hasMany / belongsToMany methods allow for linking several tables in a relationship.