By Michael Williams, Published on 05/26/2018
Sometimes when you work with relations in Laravel, a need me arise to add a constraint to the relatioship data. In Laravel terms, this is referred to as Constraining Eager Loads.
Assumming that you have a User and Post Model. One might build a query as such to retrieve active posts for a specific user.
$this->posts->whereStatus('published')->whereUserId($userId)->get();When loading the User with the Post relationship, we can also get the published posts only by running:
$this->user->with(['posts' => function ($query) {
$query->where('status', 'published');
}])->get();There also may be a time where we only want to return specific columns from a relationship result set. That can be achieved as follows:
$this->user->with(['posts' => function ($query) {
$query->select('id', 'title');
}])->get();