数据库与Eloquent laravel同步

Question

I am trying to save the input of some checkboxes.

I have a table users_cities as:

id_user | id_city
--------+---------
   1    |    1
   1    |    2
   2    |    1

And I have a view which brings three checkboxes.

city1 city2 city3, on that case for id_user = 1 would bring city1 and city2 checked.

what I am trying to do is, if the user selects box 3 and uncheck box 2 or just select box 3, the Eloquent would recognise and sync the data with the database.

public function update($id)
{
    $city[] = \App\City::find($id);

    $input = Request::all();

    //Tried:      $city->sync($input)
    //Also tried: $city->delete(); $city->save($input);
    return redirect()->back();
}

I have the id_user on the $city variable and the cities on $input but I can't get this to work.

VIEW:

@extends('welcome')

@section('content')

    <h1>Atualizar cidades</h1>


    @foreach ($city as $citySelect)

        <?php $number[] = $citySelect->id_city; ?>

    @endforeach 

    {!! Form::model($city, ['route' => ['cities.update', $citySelect->id_user]]) !!}

    @foreach ($cidades as $cidadesnome)

        {!! Form::checkbox($cidadesnome->id, $cidadesnome->name, (in_array($cidadesnome->id, $number)), ['class' => 'field']) !!}{!! $cidadesnome->name !!}

    @endforeach

    <button class="btn btn-success" type="submit"> 
        Atualizar Cidades
    </button>
    {!! Form::close() !!}

@stop

Relations:

public function cities() {
    return $this->belongsToMany('City', 'users_cities', 'id_city', 'id_user');
}

public function users() {
    return $this->belongsToMany('Users', 'users_cities', 'id_user', 'id_city');
}

Answer 1

I have the id_user on the $city variable and the cities on $input but I can't get this to work.

That is not posible since you used $city[] = \App\City::find($id); and therefore $city is not id_user but an array that contains one instance of App\City.

What you need to do in order to sync the cities of an user whose id is in $id is:

public function update($id)
{
    $user = \App\User::findOrFail($id);
    $input = Request::all();
    $user->cities()->sync($input['cities']);

    return redirect()->back();
}

You also need to change your checkboxes name to send an array of cities and have the name cities[]

@foreach ($cidades as $cidadesnome)
    <label>
    {!! Form::checkbox('cities[]', $cidadesnome->id, (in_array($cidadesnome->id, $number)), ['class' => 'field']) !!}{!! $cidadesnome->name !!}
    </label>
@endforeach

All that assuming you defined the proper relationships in your models. I see you are not following Eloquent naming convention for your column names. I highly recommend you follow them. They will make your relationships definitions much easier.