count post with all categories in laravel 5 - php

Question

hello I have two tables one is categories another is ads_listings. In categories table there are 4 columns id, parent_category_id, category_slug, category_title. Here parent_category_id 0 indicates main category and rest of the thing indicates sub category. user post store in ads_listings table. Now I want to find post with specific categories like this
vehicles(3)
cars(2)
motorbike(1)
cycle(0)
here the problem is my code found only subcategories which have posts. my controller code is
public function countListingsByCategories()
{
return DB::table("ads_listings")
->select("categories.category_title",DB::raw("COUNT(ads_listings.category_id) as num_listings"))
->join("categories", "categories.id","=","ads_listings.category_id")
->groupBy("ads_listings.category_id")
->get();
}
views code is:
<ul class="row catelist">
#if(isset($categoriesNumListings) && count($categoriesNumListings))
#foreach($categoriesNumListings as $categoriesNumListings)
<li class="col-md-12">{{ $categoriesNumListings->category_title }} <span>({{ $categoriesNumListings->num_listings }}Listings )</span></li>
#endforeach
#endif
</ul>
my Category table is:
ads_listing table is:

Answer 1

I think the problem is that you are counting ad_listings when you primarily want to count categories and get the number of ad_listings, I would do something like:
Second shot :)
public function countListingsByCategories()
{
return DB::table("categories")
->select("categories.category_title",
DB::raw("categories.title,
CASE
WHEN (categories.parent_id = 0)
THEN (SELECT count(ads_listings.category_id)
FROM ads_listings
WHERE ads_listings.category_id in
(SELECT subcategory.id
FROM categories subcategory
WHERE subcategory.parent_id = categories.id))
ELSE (SELECT COUNT(ads_listings.category_id)
FROM ads_listings
WHERE ads_listings.category_id = categories.id)
END as numberOfPosts,
CASE
WHEN (categories.parent_id = 0)
THEN (select 'Category')
ELSE (select 'subCategory')
END as type
FROM categories"))
->get();
}