Error when updating database after deploying to server. Laravel 5

Question

I have one form that adds data to two different tables (Articles & Deals). An Article has many deals. A deal has one Article. There are multiple deals with different dealnames that the user inputs on the create and edit form. I can update the 'deals' part of my database fine in my local/vagrant dev environment but I get a ' Creating default object from empty value ' error when I try on my live site. It says the problem is in the update function of my Articles Controller .

I'm using Laravel 5.

The Articles Table has: id(primary) , title , image , description , address .

The Deals table has: id(primary) , dealname , article_id (index) , dayID .

The only difference I can see between my dev and live environment is that the index (article_id) on the 'Deals' table doesn't have a key icon next to it in PHPMyAdmin. But the foreign key r/ship is set correctly.

You can see all the code here: https://github.com/lakemck/gethappy

Articles Controller- Update

 public function update(ArticleRequest $request, $id)
    {
    $article = Article::findOrFail($id);

      if( $request->hasFile('image') ){
            // photo saving stuff.
       }
$article->update($request->all());
for($i = 0; $i < sizeof($request->input('dealname')); $i++) {
//Error is supposedly on the next line.
    $article->deals->where('dayID',($i + 1))->first()->dealname = $request->input('dealname')[$i];
    $article->deals->where('dayID',($i + 1))->first()->save();
    }
        return redirect('/');
    }

Form

{!! Form::model($article, ['route' => ['articleUpdate_path', $article->id], 'files' => true, 'method' => 'PATCH']) !!}

    {!! Form::label('title','TITLE') !!}
    {!! Form::text('title', null, ['class' => 'form-control']) !!}
    {!! $errors->first('title','<p class="error">:message</p>')!!}

    {!! Form::label('image','PHOTO') !!}
    {!! Form::file('image', null, ['class' => 'form-control']) !!}

    {!! Form::label('description','DESCRIPTION') !!}
    {!! Form::textarea('description', null, ['class' => 'form-control']) !!}

@foreach ($article->deals as $deal)

    @if($deal->dayID == '1' )
     {!! Form::label('dealname','Monday') !!}
     {!! Form::text('dealname[]', $deal->dealname, null, ['class' => 'form-control', 'id' => '1']) !!}
     @endif

    @if($deal->dayID == '2' )
     {!! Form::label('dealname','Tuesday') !!}
     {!! Form::text('dealname[]', $deal->dealname, null, ['class' => 'form-control', 'id' => '2']) !!}
    @endif
    @if($deal->dayID == '3' )
      {!! Form::label('dealname','Wednesday') !!}
      {!! Form::text('dealname[]', $deal->dealname, null, ['class' => 'form-control', 'id' => '3']) !!}
    @endif
@endforeach

    {!! Form::label('address','ADDRESS') !!}
    {!! Form::text('address', null, ['class' => 'form-control']) !!}

    {!! Form::close() !!}

Article Model

class Article extends Model
{
    public function deals()
    {
        return $this->hasMany('App\Deal');
    }  
protected $fillable = array('title', 'photo', 'description', 'address'); 
}

DEAL MODEL

class Deal extends Model
{
    public function article()
    {
        return $this->belongsTo('App\Article')->withTimestamps();
    }
    protected $fillable = array('dealname', 'article_id', 'dayID'); 
}

Answer 1

In the end I had to change the code in my ArticlesController update function to this:

for($i = 0; $i < sizeof($request->input('dealname')); $i++) {

    $deal = $article->deals()->where('dayID', $i + 1)->first();
    $deal->dealname = $request->input('dealname')[$i];
    $deal->save();
    }
        return redirect('/');
    }

Note the brackets on the deals().