Laravel Object queries - 3 tables - php

Question

I have three tables like this:
**Users**
id
**Posts**
id
user_id
**Favorites**
id
user_id
post_id
Currently, I made it so when I query my posts for display, it pulls all the related user data who created the post with that row which is great! But what I'm trying to do now is also add to see if the user Authorized (Logged in) has favorited the post (row) so I can display to that they already favorited it. I don't want to re-query for every post (i think its called the N+1 problem?). I'm using Laravel4
Post model
class Post extends Eloquent{
public function user(){
return $this->belongsTo('User');
}
User model
public function posts(){
return $this->hasMany('Post');
}
PostsController
public function index()
{
$posts = Post::with('user')->paginate(25);
return View::make('index', compact('posts'));
}

Answer 1

Step 1. Add favorites relationship in Post model.
public function favorites() {
return $this->hasMany('Favorite');
}
When querying the Model.
$auth_user_id = Auth::user()->id;
$posts = Post::with(array('user', 'favorites' => function($query) use ($auth_user_id){
$query->where('user_id', '=', $auth_user_id);
}))->get();
For more information refer to the eager load constraints,
http://laravel.com/docs/eloquent#eager-loading

Answer 2

Adding a many-to-many relationship using the favorites table as pivot would be one approach.
Add favorites relationship in User model:
public function favorites() {
return $this->belongsToMany('Post', 'favorites');
}
You should then be able to get all favorites by simply accessing
Auth::user()->favorites
To find whether the current post is a favorite, use
$isFavorite = Auth::user()->favorites->has($post->id);