Defining and Using Many-to-Many Relationships in Laravel Eloquent

Laravel's Eloquent ORM supports many-to-many relationships, which link two models through an intermediate table (e.g., users, roles, role_user).

In the User model you define a roles() method that returns $this->belongsToMany('App\\Role'); similarly, the Role model defines a users() method that returns $this->belongsToMany('App\\User').

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function roles()
    {
        return $this->belongsToMany('App\\Role');
    }
}
?>

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;

class Role extends Model
{
    public function users()
    {
        return $this->belongsToMany('App\\User');
    }
}
?>

After defining the relationship you can retrieve related records via the dynamic property $user->roles and chain query constraints such as $user->roles()->orderBy('name')->get() or filter by pivot columns with wherePivot('approved', 1) and wherePivotIn('priority', [1,2]).

The intermediate table can be customized by passing its name and foreign key columns to belongsToMany, for example

$this->belongsToMany('App\\Role', 'role_user', 'user_id', 'role_id')

. Additional pivot columns can be accessed using withPivot('column1', 'column2'), and timestamps can be automatically maintained with withTimestamps().

You may rename the pivot accessor with as('subscription') and retrieve it as $podcast->subscription, allowing more expressive code when the pivot represents a specific concept.

For advanced scenarios you can define a custom pivot model by chaining using('App\\UserRole') on the relationship; the custom model must extend Illuminate\Database\Eloquent\Relations\Pivot and can contain additional logic or attributes.

<?php
namespace App;
use Illuminate\Database\Eloquent\Relations\Pivot;

class UserRole extends Pivot
{
    // Custom pivot logic here
}
?>