Laravel Relationship Union: One Relationship with two tables in a model - laravel

Question

Lets supose this scenery:
We have 3 models -> User, Role and Permission.
Relationships
User has one to many relationship with Role.
Role has many to many relationship with Permission
User has many to many relationship with Permission.
The final purpose to the User -- Permisson relationships is to override the permission assigned to the user through his role. Just an exception for this User.
I am trying to to something like this:
public function permissions () {
return $this->hasManyThrough('App\Permission', 'App\Role')->merge($this->permissionOverrides);
}
In this case when I try to eager load the model permissions Laravel throws an error 'cause permissions is not detected as a relationships.
In the other hand, what if we change User -- Role relationship to many to many?
Thanks a lot for your knowledge!
EDIT
Role Relationships
public function permissions() {
return $this->belongsToMany('App\Permission')->withTimestamps();
}
Permission relationships
public function roles() {
return $this->belongsToMany('App\Role')->withTimestamps();
}
User relationships
public function roles() {
return $this->belongsToMany('App\Role')->withTimestamps();
}
public function permissionOverrides() {
return $this->belongsToMany('App\Permission')->withTimestamps();
}
The question is how to make the permissions() relationship merging the role permissions and the user permissions.
BETTER EXPLANATION
Due to misunderstanding shown in comments I will try to exlain this better. I had set all the relations between App\User and App\Role; I also had set the the relationship between App\Role and App\Permission. I can do right now:
$user->role->permissions;
For obtaining this I have configured the pivot table permission_role which stores the relation.
Thats not the case. What I want is to add one more var to the equation. Now I want to have the ability to override the role permissions adding a relationship between App\User and App\Permission. I have the pivot table permission_user and the relation stablished:
public function permissionsOverride() {
return $this->belongsToMany('App\Permission');
}
The REAL QUESTION is how to obtain all the permissions (both role permissions and overrided permissions in only ONE relationship). I mean merging both relationships.
Why I want to merge relationships? I could do a regular function to do this, but I would want to eager load this relation, Laravel way.

Answer 1

You can try like this, ManyToMany relation between User And Role, similarly ManyToMany relation between Role and Permission.
User Model
public function roles() {
return $this->belongsToMany('App\Role', 'user_role')->withTimestamps();
}
public function permissions() {
return $this->belongsToMany('App\Permission', 'permission_user')->withTimestamps();
}
Role Model
public function users() {
return $this->belongsToMany('App\User', 'user_role')->withTimestamps();
}
public function permissions() {
return $this->belongsToMany('App\Permission', 'permission_role')->withTimestamps();
}
Fetch Data
$user = User::with('permissions','roles','roles.permissions')->find(1);
$permissions = $user->permissions;
foreach($user->roles as $role){
$permissions->merge($role->permissions); //merger collection
}
dd($permissions->all());
For details you can look https://laravel.com/docs/5.6/eloquent-relationships#many-to-many
And for Collection you can look this https://laravel.com/docs/5.6/collections#method-merge