Many to many relationships are very common in web applications. For example, a user may have many roles, and a role may have many users.
In this example, we will create a many to many relationship between users and roles.
First, we will create a User model and a Role model.
User Model
belongsToMany(‘App\Role’);
}
}
Role Model
belongsToMany(‘App\User’);
}
}
Next, we will create a pivot table to store the many to many relationship.
php artisan make:migration create_role_user_table
bigIncrements(‘id’);
$table->unsignedBigInteger(‘user_id’);
$table->unsignedBigInteger(‘role_id’);
$table->timestamps();
});
}
public function down()
{
Schema::dropIfExists(‘role_user’);
}
}
Finally, we can create a seeder to populate the database with some dummy data.
‘admin’,
]);
$userRole = Role::create([
‘name’ => ‘user’,
]);
// Create users
$adminUser = User::create([
‘name’ => ‘Admin User’,
’email’ => ‘[email protected]’,
‘password’ => bcrypt(‘password’),
]);
$regularUser = User::create([
‘name’ => ‘Regular User’,
’email’ => ‘[email protected]’,
‘password’ => bcrypt(‘password’),
]);
// Assign roles to users
$adminUser->roles()->attach($adminRole);
$regularUser->roles()->attach($userRole);
}
}
Now, we can run the seeder to populate the database with the dummy data.
php artisan db:seed –class=RoleUserTableSeeder
Laravel 9 many to many relationship example; In this tutorial, you will learn laravel many to many relationship with examples.
Using belongsToMany() method, you can define many to many relationship in laravel eloquent models. And you can also insert, update and delete records from database table using many to many relationship in laravel
Laravel Eloquent Many to Many Relationship Example
In this example, you will see two tables name posts and tags.
Each post has many tags and each tag can have many posts.
To define many to many relationships, Using belongsToMany() method:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Post extends Model
{
...
public function tags()
{
return $this->belongsToMany('App\Tag');
}
}
To access the tags in the post model as follow:
$post = App\Post::find(8);
foreach ($post->tags as $tag) {
//do something
}
The inverse of Many to Many Relationship Example
The inverse of a many to many relationships can be defined by simply calling the similar belongsToMany method on the reverse model. We can illustrate that by defining posts() method in Tag model as:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Tag extends Model
{
public function posts()
{
return $this->belongsToMany('App\Post');
}
}
To access the post in the tag model as follow:
$tag = App\Tag::find(8);
foreach ($tag->posts as $post) {
//do something
}
Conclusion
In this tutorial, you have learned define many to many relationships and as well as how to use it.
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