eloquent where with relationship code example
Example 1: laravel where on relation
Event::whereHas('participants', function ($query) {
$query->where('IDUser', '=', 1);
})->get();
Example 2: how to use where relationship laravel
Event::with(["owner", "participants" => function($q) use($someId){
$q->where('participants.IdUser', '=', 1);
//$q->where('some other field', $someId);
}])