Many-to-Many relationship in Laravel - All you need to know

In this article, you will learn about Laravel's many-to-many relationship, starting from the basics and gradually progressing to more advanced concepts. We'll begin with a simple example involving users and projects, where we will establish a relationship between users and projects using a pivot table. After setting up the relationship, we will demonstrate how to store and fetch records from the database efficiently. By the end, you will have a deep understanding of how to implement many-to-many relationships in Laravel with practical use cases.

Setting Up the Database

Our tables for projects, users and a pivot table name project_user.

Relationship Setup

here we will define many-to-many relationship using the **belongsToMany() method**.

Creating Sample Data

We will generate sample data by using factories and seeder. Now, migrate and seed the database:

Utilizing the Relationship

Now we will use our relationship to fetch the projects with users. users is our relationship which is present in Project model. Now lets goto **welcome.blade.php** and paste this code. 

1 - Adding timestamps column in Pivot Table

Now let's add time timestamps column in pivot table. Then in the model we need to attach **withTimestamps()** in the model function. And in the welcome.blade.php , you need to show created_at column.  If you want to change pivot name from the loop, then you need to attach 1 more function in Project model. Now your welcome.blade.php will look like this The output will be the same.

2 - Adding is_manager column in Pivot Table

Let's modify project_user table . Goto Migrations, add 1 more column in the project_user table. ```php Schema::create('project_user', function (Blueprint $table) { $table->foreignId('project_id')->constrained(); $table->foreignId('user_id')->constrained(); $table->boolean('is_manager')->default(false); $table->timestamps(); }); ``` Goto Seeder attaches manager to user in random order. ```php $projects = \App\Models\Project::factory(10)->create(); foreach ($projects as $project) { $users = User::inRandomOrder()->take(rand(1, 3))->pluck('id'); foreach ($users as $user) { $project->users()->attach($user,['is_manager'=>rand(0,1)]); } } ``` Goto your Project model, create a new relationship function named managers. ```php public function managers(): BelongsToMany { return $this->belongsToMany(User::class, 'projects_user', 'project_id', 'user_id') ->withTimestamps() ->withPivot(['is_manager']) ->as('project_user'); } ``` Now go to your controller and call managers function. ```php public function index() { $projects = Project::with('managers')->get(); $data = ['projects' => $projects]; return view('welcome', $data); } ``` Now go to **welcome.blade.php** ```php @foreach ($projects as $project) {{ $loop->index + 1 }} {{ $project->name }}

@foreach ($project->managers as $manager)
• {{ $manager->name }} ({{ $manager->project_user->is_manager }})
@endforeach

@endforeach ```  You haven't seen pivot model; I did not create a pivot model for projects and users. This is why we are not calling any relation from the pivot table. Now we will create a separate model for the pivot table. #### 3 - Adding Relationship(manager_id) with Pivot Table ```php php artisan make:model ProjectUser ``` ```php class ProjectUser extends Pivot { use HasFactory; public function manager(): BelongsTo { return $this->belongsTo(User::class, 'manager_id'); } } ``` In this model , we have extended this class from model to pivot and added a new relationship with managers. Now goto to **Database/Migration/project_user.php** ```php Schema::create('project_user', function (Blueprint $table) { $table->foreignId('project_id')->constrained(); $table->foreignId('user_id')->constrained(); $table->boolean('is_manager')->default(false); $table->timestamps(); }); ``` After that go to your **Project.php** Model and attach a new function in users relationship. ```php public function users(): BelongsToMany { return $this->belongsToMany(User::class, 'project_users', 'project_id', 'user_id') ->withTimestamps() ->withPivot('manager_id') ->using(ProjectUser::class); } ``` After that, goto to your **ProjectSeeder** and attach **manager_id** in random order. ```php $projects = \App\Models\Project::factory(10)->create(); foreach ($projects as $project) { $users = User::inRandomOrder()->take(rand(1, 3))->pluck('id'); foreach ($users as $user) { $project->users()->attach($user, ['manager_id' => User::inRandomOrder()->first()->id]); } } ``` Now goto your **HomeController** ```php public function index() { $projects = Project::with('users')->get(); $data = ['projects' => $projects]; return view('welcome', $data); } ``` and in the **welcome.blade.php** ```php @foreach ($projects as $project) {{ $loop->index + 1 }} {{ $project->name }}

@foreach ($project->users as $user)
• {{ $user->name }}({{ $user->pivot->manager->name }})
@endforeach

@endforeach ```