BUT2/mini-crm/app/Http/Controllers/ClientsController.php

<?php

namespace App\Http\Controllers;
use App\Models\Client;
class ClientsController extends Controller
{
    public function index()
    {
        return $this->renderClients(Client::all());
    }

    public function paris()
    {
        return $this->renderClients(Client::where('city', 'Paris')->get());
    }

    public function martin()
    {
        return $this->renderClients(Client::where('name', 'like', '%Martin%')->get());
    }

    public function second()
    {
        return $this->renderClients(collect([Client::findOrFail(2)]));
    }

    private function renderClients($clients)
    {
        return view('clients.index', compact('clients'));
    }
}