Laravel: Improved pivot query - laravel

Question

I am successfully querying following and it create 130 queries, I want to optimise it and reduce the number of queries, I have set upped the model and controllers following way.
Post Modal
class Post extends Eloquent {
public function Categories () {
return $this->belongsToMany('Category', 'category_post');
}
}
Category Modal
class Category extends Eloquent {
public function posts () {
return $this->belongsToMany('Post', 'category_post');
}
}
and in the Controller, I am using following query, what following query does is, querying the results based on category id.
$category = Category::with('posts')->where('id','=',$id)->paginate(10)->first();
return Response::json(array('category' => $category));
If anyone can give me a hand to optimise the query, would be really greatful.

Answer 1

You are wrong, it doesn't create 130 queries.
It will create the following 3 queries:
select count(*) as aggregate from `categories` where `id` = '5';
select * from `categories` where `id` = '5' limit 10 offset 0;
select `posts`.*, `posts_categories`.`category_id` as `pivot_category_id`, `posts_categories`.`post_id` as `pivot_post_id` from `posts` inner join `posts_categories` on `posts`.`id` = `posts_categories`.`post_id` where `posts_categories`.`category_id` in ('5');
But the question is what exactly you want to paginate. Now you paginate categories and it doesn't make much sense because there's only one category with selected $id.
What you probably want to get is:
$category = Category::where('id','=',$id)->first();
$posts = $category->posts()->paginate(10);
and this will again create 3 queries:
select * from `categories` where `id` = '5' limit 1;
select count(*) as aggregate from `posts` inner join `posts_categories` on `posts`.`id` = `posts_categories`.`post_id` where `posts_categories`.`category_id` = '5';
select `posts`.*, `posts_categories`.`category_id` as `pivot_category_id`, `posts_categories`.`post_id` as `pivot_post_id` from `posts` inner join `posts_categories` on `posts`.`id` = `posts_categories`.`post_id` where `posts_categories`.`category_id` = '5' limit 10 offset 0;
If you would like to improve it, you will probably need to not use Eloquent in this case and use join - but is it worth it? You would now need to manually paginate results without paginate() so it would probably won't be want you want to achieve.
EDIT
What you probably do is:
you get all posts that belongs to the category (but in fact you want to paginate only 10 of them)
for each post you want do display all categories it belongs to.
To lower number of queries you should use:
$category = Category::where('id','=',$id)->first();
$posts = $category->posts()->with('categories')->paginate(10);
and to display it you should use:
foreach ($posts as $p) {
echo $p->name.' '."<br />";
foreach ($p->categories as $c) {
echo $c->name."<br />";
}
}
It should lower your number queries to 4 from 130