There is one problem which I can't solve. I need to show a response only for users whose user_id was written in 'recipient' field.

First step : I am writing the user_id into a table using json array

Appform.blade.php

       <div class="form-group">
    {{ Form::label('recipient', 'Checking') }}
   <select id="recipient" name="recipient[]" required class="form-control" multiple>
 @foreach ($recipient as $user)
     <option value="{{ $user->id }}">{{ $user->first_name }}</option>
 @endforeach
  </select>
@if($errors->has('recipient'))
 {{ $errors->first('recipient') }}
 @endif
</div>

Controller.php

   public function postAppForm()
{
$data = Input::all();
$cityId             = Input::get('city');
$recipient          = Input::get('recipient');

$rules = array(
    'city'           => 'required',
    'recipient'      => 'required',
);

$recipient1 = json_encode($recipient);

$validator = Validator::make($data, $rules);
if($validator->passes()) {

    $posts = new Posts;
    $posts->recipient   = $recipient1;
    $city               = City::find($cityId);

    $city->posts()->save($posts);
    return Redirect::to('appform')->with('global-success', 'Заявка отпарвленна');

} else {
    return Redirect::back()->withErrors($validator)->withInput();
}


public function application()

{

     $recipient = DB::table('posts')->groupBy('recipient')-   >lists('recipient');

 }

And I get ["18","19","20"] - user_id for my post, but I don't know how to show my posts only for that users_id?