Error when updating database after deploying to server. Laravel 5 - php

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().