Laravel 4 and Eloquent: retrieving all records and all related records - orm

Question

I have two classes: Artist and Instrument. Each Artist can play one or more Instruments. And each Instrument can be assigned to one or more Artists. So, I've set up the following Classes:
Artist.php
public function instruments() {
return $this->belongsToMany('App\Models\Instrument');
}
Instrument.php
public function artists() {
return $this->belongsToMany('\App\Models\Artist');
}
Then I have three database tables:
artists: id, firstname, lastname, (timestamps)
instruments: id, name
artist_instrument: id, artist_id, instrument_id
I'm able to successfully retrieve a one artist and their associated instruments like so:
ArtistController.php
$artist = Artist::find($artist_id);
$instruments = $artist->instruments()->get();
return \View::make('artists')->with('artists', $artists)->with('instruments', $instruments);
I have 3 questions:
In my view, I can output the $artist like:
{{ $artist->firstname }}
and I can iterate through $instruments like:
#foreach ($instruments as $instrument)
<h2>{{ $instrument->name }}</h2>
#endforeach
but is it possible to iterate over $artist (I know there's only one — see #2) and for each $artist iterate over their $instruments?
In my controller, how would I get all artists and for each of those their associated instruments with the end goal of iterating through them in my view as described in #1.
Is it possible to only retrieve specific columns in the above example of ArtistController.php? I've tried this:
$artist = Artist::where('id', $artist_id)->get('firstname');
$instruments = $artist->instruments()->get();
return \View::make('artists')->with('artists', $artists)->with('instruments', $instruments);
but I get an error saying Collection::instruments() is undefined.
I'm assuming there's something not right in my model relationships. I've also tried defining my relationship in Artist.php with a hasMany (I think it makes more sense to say "Each Artist hasMany Instruments", but that gives me an error because it's expecting a table named artists_instruments and it's also trying to retrieve columns that wouldn't exists in that table (like name).

Answer 1

Your model relationships are fine.
Controller:
$artists = Artist::with('instruments')->get();
return \View::make('artists')->withArtists($artists);
View:
#foreach ($artists as $artist)
<h1>{{ $artist->firstname }}</h1>
#foreach ($artist->instruments as $instrument)
<h2>{{ $instrument->name }}</h2>
#endforeach
#endforeach