Multiple Roles per User?

Currently, our project has a users.role_id column. But what if a user can have many roles instead of just one?

In this lesson, let's change a one-to-many to a many-to-many relationship.

Migration: From One Foreign Key to Pivot Table

The obvious first step is to change the migration from users.role_id to a pivot table called role_user.

Migration

Schema::table('users', function (Blueprint $table) {
    $table->foreignId('role_id')->default(1)->constrained();
});
 
Schema::create('role_user', static function (Blueprint $table) {
    $table->id();
    $table->foreignId('user_id')->constrained();
    $table->foreignId('role_id')->constrained();
});

Notice: I added the id() column as an auto-increment, but it's optional and just a personal preference.

User Model Relationship: From BelongsTo to BelongsToMany

We also changed the relationship in the Model, changing the method name from role() to roles() and removing the old fillable field.

use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 
// ...
 
protected $fillable = [
    'name',
    'email',
    'password',
    'role_id', 
];
 
// ...
 
protected $with = [
    'roles'
];
 
public function role(): BelongsTo
{
    return $this->belongsTo(Role::class);
}
public function roles(): BelongsToMany
{
    return $this->belongsToMany(Role::class);
}

Notice: I also added a $with array, so user would be always loaded with their roles as a relationship. This is a bit "risky" and may cause unnecessary loading if you want to have just Users on other pages of your application. So, use it with caution.

Policy: Adding Collections

Did you see that $with from the above? It allows us to have a $user->roles Collection in multiple Policy methods without running into the N+1 Query problem.

From there, we can use a Collection method contains() to check for the roles we want.

Next, we have to modify our Policy conditions to use...