Call to a member function update() on null LARAVEL - php

Question

I tried to update specific item but it was error 'Call to a member function update() on null'.
I tried to change ->update($data) with ->insert($data) before and it works.
Controller:
public function update(Request $request, $id)
{
$this -> validate($request, array(
'gamename' => 'required|min:3',
'price' => 'required|int|min:1',
'genre' => 'required',
'releaseddate' => 'required|date',
'picture' => 'required|mimes:jpeg,jpg,png,gif'
));
$gamename = $request->input('gamename');
$genre = $request->input('genre');
$price = $request->input('price');
$releaseddate = Carbon::parse($request->input('releaseddate'));
$picture = $request->file('picture')->getClientOriginalName();
$data=array('gamename' => $gamename, 'genre'=>$genre, 'price'=>$price,'releaseddate'=>$releaseddate,'picture'=>$picture );
DB::table('games')->join('genres', 'games.genreid', '=', 'genres.genreid')->find($id)->update($data);
return redirect('managegame');
}
View:
<form action="/update/{id}" method="post" id="registerform" enctype="multipart/form-data">
<div class="errorpop{{ $errors->has('genre') ? ' has-error' : '' }}">
<label for="genre" class="">Genre</label>
<div class="">
#foreach($genres as $genre)
<option value="{{ $genre->genreid }}">{{ $genre->genre }}</option>
#endforeach
#if ($errors->has('genre'))
<span class="help-block">
<strong>{{ $errors->first('genre') }}</strong>
</span>
#endif
</div>
</div>

Answer 1

{id} not a value. You must have value for {id} .
Example: action="/update/1"
<form action="/update/1" method="post" id="registerform" enctype="multipart/form-data">
<div class="errorpop{{ $errors->has('genre') ? ' has-error' : '' }}">
<label for="genre" class="">Genre</label>
<div class="">
#foreach($genres as $genre)
<option value="{{ $genre->genreid }}">{{ $genre->genre }}</option>
#endforeach
#if ($errors->has('genre'))
<span class="help-block">
<strong>{{ $errors->first('genre') }}</strong>
</span>
#endif
</div>
</div>
Then to update you use method where('id', $id) replace find($id)
DB::table('games')->join('genres', 'games.genreid', '=', 'genres.genreid')->where('id', $id)->update($data);
https://laravel.com/docs/5.5/queries#updates

Answer 2

Make sure you got the object
$game = DB::table('games')->
join('genres', 'games.genreid', '=', 'genres.genreid')->where('id',$id)->get();
//make sure you have the desired object.then
$game->update($data);

Answer 3

I'm nor sure this line works as you expect
DB::table('games')->join('genres', 'games.genreid', '=', 'genres.genreid')->find($id)->update($data);
What are you trying to update? games or genres ? You can't update 2 tables at once like that. You'd need to find the games row to update, update that that, and the joined table row, and update that, cannot do it all at once.
But the fact that you're trying to update 2 tables from one simple form, in the same method suggests that your tables is not properly laid out?

Answer 4

id)->update($data);
return redirect('managegame');
}
View:
has('genre') ? ' has-error' : '' }}">
Genre
<div class="">
#foreach($genres as $genre)
<option value="{{ $genre->genreid }}">{{ $genre->genre }}</option>
#endforeach
#if ($errors->has('genre'))
<span class="help-block">
<strong>{{ $errors->first('genre') }}</strong>
</span>
#endif
</div>
</div>