is there any function to check if the input data exists in the database using laravel

i have a users table in database has 9 rows (user name,email, adress,...). I want the user to enter 1 row (user name) so i have to take this input and return the user to another route with the whole 9 raws (user name, email, adress,...), i already imported model in control and im stucked now

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\user;

  public function index(Request $request)

      {
          $user = DB::table('users')->get();
    

          return view('userhome', ['users' => $user]);


      }

via Chebli Mohamed