Mutli relationships with Eloquent and Laravel - laravel

Question

I have 6 tables:
permissions:
id
permission_name
roles:
id
role_name
user_roles:
id
user_id
role_id
user_permissions:
id
user_id
permission_id
role_permissions:
id
role_id
permission_id
users:
id
username
email
Now I like to add a custom function into my Eloquent model for permissions named getUsersWithPermission().
Now it is possible that user has the permission by the role he has given (user table join on user_roles, join that table on role_permissions and last that table join on permissions.
Or the user has a specific permission set in the user_permissions table (join user_permissions table on user table and join the permissions table on the user_permissions table)
How can I create a Eloquent model function that returns all the users with a specific permission say: "notification.error.process" where that is the permission name
A hasMany doesn't quite do what I want (and I cannot define multi tables in there). I am using Laravel 5.6.

Answer 1

If you defined your many-to-many relations correctly (User-Permission and User-Role-Permission), the following should do the trick:
$permissionName = 'notification.error.process';
$usersWithPermission = User::whereHas('permissions', function($query) use ($permissionName) {
$query->whereName($permissionName);
})->orWhereHas('roles.permissions', function($query) use ($permissionName) {
$query->whereName($permissionName);
})->get();

Answer 2

Try to understand your table structure using this ER diagram.
TO handle this situation, You may create 3 'Eloquent Models'
User
Role
Permission
in every model you may create belongsToMany() relationship to each other models.
one example, On 'User Model'
public function permissions()
{
// need to define any other differences in your tables foreign keys as 2nd, 3rd parameters and so on.
return $this->belongsToMany(Permission::class);
}
Now you need to get all the users 'whom has a role which has the privilege' OR 'whom directly has the privilege.
to do so.
$users = User::whereHas('privileges', function($query) {
$query->where('permission_name', 'notification.error.process');
})->orWhereHas('roles.permissions', function($query) {
$query->where('permission_name', 'notification.error.process');
})->get();
I hope you will get an idea. your code may be slightly different from mine. but this is the concept.