Eloquent Relationship Count

Question

I have a problem with Laravel 4 and Elqouent. My Models have the following relationships implemented:

User belongsToMany Role
Role belongsToMany User

I want to query for the roles and want to get the count of related users with them.

When I do the following, I have the N+1 problem:

$role = Role::has('users')->get()->each(function($role) {
    $role->user_count = $role->users()->count();
});

Is there anything I did not think about?

Answer 1

This is what you need for belongsToMany :

// Role model

// helper relation
public function usersCount()
{
    return $this->belongsToMany('User')
      ->selectRaw('count(users.id) as count')
      ->groupBy('pivot_role_id');
}

// accessor for $role->usersCount;
public function getUsersCountAttribute()
{
    if ( ! array_key_exists('usersCount', $this->relations)) $this->load('usersCount');

    $related = $this->getRelation('usersCount')->first();

    return ($related) ? $related->count : 0;
}

Then you can eager load it:

$roles = Role::with('usersCount')->get();

// pick one, for example
$roles->first()->usersCount; // int
$roles->last()->usersCount; // 0 if no related users were found

---

You current solution unfortunately is pretty bad, because it queries the db for each role.

The code above lets you fetch that count for all the roles with just a single query. Another thing is that you don't load all the related users if not necessary, so it doesn't eat your memory (in case it would matter).

Answer 2

Despite my appreciation of you guys helping me, neither of your solutions actually did the trick unfortunately.

I have found another question+answer that helped me, though.

Here is the solution that is perfectly working what I wanted:

Role::join('assigned_roles', 'assigned_roles.role_id', '=', 'roles.id')
        ->groupBy('roles.id')
        ->orderBy('user_count', 'desc')
        ->orderBy('name', 'asc')
        ->get(['roles.*', DB::raw('COUNT(assigned_roles.id) as user_count')]);

Answer 3

Use withCount()

  $companies = $this->company
                        ->with("municipality.province")
                        ->withCount("projects","users")
                        ->get();

this return

{
        "id": 1,
        "name": "TEST",
        "fiscal_id": "0000000",
        "image_path": "/assets/icons/svg/energy.svg",
        "municipality_id": 1111,
        "telephone": null,
        "is_active": true,
        "sector": "consultancy",
        "type": "legal",
        "created_at": "2022-07-16T16:05:38.000000Z",
        "updated_at": "2022-07-16T16:05:38.000000Z",
        "projects_count": 2,
        "users_count": 2,
        "image_src": "http://localhost//assets/icons/svg/energy.svg"
    }