Laravel 5.5 - Blade templates, querying deeper into a hasMany relationship - laravel

Question

I am wondering if I can query a hasOne -> hasMany relationship in blade. I can currently get a count on how many models exist in my blade using "$participant->messages->count()" but I would like to check the model and count other things. For instance I would like to run the following query in blade:
{!! $participant->messages->where($this->messages->mediaURL, "=", null)->count() !!}
I get the following error:
Property [mediaURL] does not exist on this collection instance.
Here is my controller function
public function showParticipants()
{
$participants = Participant::all();
// $messages = $participants->participant_id->messages;
return view('home')->with(['participants'=> $participants, 'messages'=>'hi']);
}
Part of my Participant model:
public function messages()
{
return $this->hasMany('App\Message', 'message_id', 'participant_id');
}
Part of my Message model:
public function participant()
{
return $this->belongsTo(Participant::class);
}
My message table structure:
public function up()
{
Schema::create('messages', function (Blueprint $table) {
$table->engine = 'InnoDB';
$table->increments('id');
$table->integer('message_id')->unsigned();
$table->string('message_content')->nullable();
$table->string('mediaSID')->index()->nullable();
$table->string('messageSID')->index()->nullable();
$table->string('mediaURL')->index()->nullable();
$table->binary('media')->nullable();
$table->string('filename')->index()->nullable();
$table->string('MIMEType')->nullable();
$table->timestamps();
});
Schema::table('messages', function($table) {
$table->foreign('message_id')->references('participant_id')->on('participants')->onDelete('cascade');
});
}
My Participant DB structure:
public function up()
{
Schema::create('participants', function (Blueprint $table) {
$table->engine = 'InnoDB';
$table->string('participant_id')->unique();
$table->dateTime('appointmentDate')->nullable();
$table->dateTimeTz('timezoneOffset')->nullable();
$table->dateTime('appointmentDate_twoWeeks')->nullable();
$table->dateTime('notificationTime')->nullable();
$table->integer('notificationTally')->nullable();
$table->boolean('studyCompleted')->default(0);
$table->boolean('subscribed');
$table->timestamps();
});
}
My blade just to give all info:
#isset($participants)
#foreach ($participants as $participant)
<tr>
<td>
{!! $participant->participant_id !!}
</td>
<td>
{!! $participant->subscribed !!}
</td>
<td>
{!! $participant->notificationTime !!}
</td>
<td>
{!! $participant->notificationTally !!}
</td>
<td>
{!! $participant->studyCompleted !!}
</td>
<td>
{!! $participant->messages->count() !!}
</td>
<td>
{!! $participant->messages->where($participant->messages->mediaURL, "=", null)->count() !!}
</td>
</tr>
#endforeach
#endisset

Answer 1

I believe the issue is $this->messages->mediaURL. With the Query Builder, if you're wanting to refer to a column on a table you would just need to pass it a string. Also when you're querying a relationship you should use the method and not the property e.g. $participant->messages(). Lastly, when querying for a null column you can use the whereNull method.
{!! $participant->messages()->whereNull('mediaURL')->count() !!}

Answer 2

You are using the "magic" __get() on messages that returns a collection because it is a has many relationship.
$participant->messages->where($this->messages->mediaURL, "=", null)->count()
should be
$participant->messages()->where($participant->messages()->first()->mediaURL, "=", null)->count()