Get results from joined tables - php

Question

In my laravel app I track lesson enrollment and active subscriptions in different tables.
A lesson is defined by lesson_types table which has columns like this:
lesson_types
id | name | sub_plan
Enrollemnts are defined in enrolls table with columns like this:
enrolls
id | user_id | lesson_type_id
and my subscriptions table has columns like this:
subscriptions
id | name | sub_plan | user_id
Tables are connect like this:
enrolls has 'lesson_type_id' which is 'id' of lesson_types table
sub_plan column in lesson_types is the same as sub_plan in subscriptions
Sample database data in tables:
ennrolls
id user_id lesson_type_id
1 1 1
2 1 2
3 2 1
lesson_types
id name sub_plan
1 Lesson 1 plan_1337
2 Lesson 2 plan_1338
3 Lesson 3 plan_1339
subscriptions
id name sub_plan user_id
1 Sub 1 plan_1337 1
I tried to get all enrollments like this:
$enrolled = DB::table('enrolls')->where('user_id', $userId)
->leftJoin('lesson_types', 'id', '=', 'lesson_type_id')
->select('name');
But I need to get them without subscriptions...
What i want to achieve is:
Get all 'lesson_types' names where user is subscribed
Get all 'lesson_types' names where user has enrolled but not subscribed
Get all 'lesson_types' where user is not enrolled

Answer 1

You can Achieve the above scenario using Laravel Eloquent. Laravel has facilitated a lot of more in-built ORM methods. So We don't need to write manual SQL codes. Don't reinvent the wheel
Enrolls Model
namespace App;
use App\User;
use App\LessonType;
use App\Subscription;
use Illuminate\Database\Eloquent\Model;
/**
*
*/
class Enroll extends Model
{
public function lessonType()
{
return $this->belongsTo(LessonType::class);
}
public function users()
{
return $this->hasMany(User::class);
}
}
Lesson Types Model
namespace App;
use App\Enroll;
use App\Subscription;
use Illuminate\Database\Eloquent\Model;
/**
*
*/
class LessonType extends Model
{
public function enrolls()
{
return $this->hasMany(Enroll::class);
}
public function subscription()
{
return $this->belongsTo(Subscription::class, 'sub_plan','sub_plan');
}
}
Subscriptions Model
namespace App;
use App\User;
use App\LessonType;
use Illuminate\Database\Eloquent\Model;
/**
*
*/
class Subscription extends Model
{
public function lessonType()
{
return $this->hasMany(LessonType::class);
}
public function user()
{
return $this->belongsTo(User::class);
}
}
In Constroller or Repository
LessonType::select('name')->has('subscription.user');
LessonType::select('name')->doesntHave('subscription.user');
LessonType::select('name')->doesntHave('enrolls.users');
FYI :
Laravel Eloquent Relationships
Follow this approaches. Take it as Best Practice