Laravel hasmanythrough or mysql groupby - php

Question

I have three tables
category
id | category_name | created_at | updated_at
profile
id | category_id | profile_name | created_at | updated_at
photos
id | profile_id | photo_name | photo_path | photo_type | created_at | updated_at
Now i need to list photos by category and also only one photo from each profile by photo_type
I have tried using hasManyhrough but descending by created_at not working
public function categoryPhotos()
{
return $this->hasManyThrough(ProfilePhoto::class,Profile::class);
}
$response=Category::with(['categoryPhotos'=>function($query){
$query->where('profile_photos.photo_type',2);
$query->orderBy('profile_photos.created_at','ASC');
$query->groupBy('profile_photos.profile_id');
}])->whereHas('categoryPhotos')->get();
if its not possible via laravel relation then mysql query also fine for me.Thank you

Answer 1

Possible solution (if I understand the task correctly) may be
SELECT *
FROM category ca
JOIN profile pr ON ca.id = pr.category_id
JOIN photos ph ON pr.id = ph.profile_id
JOIN ( SELECT ph1.profile_id, MAX(ph1.id) id
FROM photos ph1
JOIN ( SELECT profile_id, MAX(created_at) created_at
FROM photos
WHERE phototype=2
GROUP BY profile_id ) sq1 ON ph1.profile_id = sq1.profile_id
AND ph1.created_at = sq1.created_at
WHERE ph1.phototype=2
GROUP BY ph1.profile_id ) sq2 ON ph.id = sq2.id
Explanations.
Subquery sq1 selects last created_at for each profile for photos with phototype=2.
Subquery sq2 takes this result and gets maximal id for photos which's profile and datetime matched those obtained in sq1 (if more than 1 photo matches the conditions, this subquery selects one of them).
FROM category ca
JOIN profile pr ON ca.id = pr.category_id
JOIN photos ph ON pr.id = ph.profile_id
collects all possible combined rows - for each category it gets all related profiles with all related photos. Then we join our subquery, which filters this total list and gets only one row for each (category, profile) pair with the photo matched our conditions (or, if none such photo, none pair is selected).
Test it in this pure SQL form (does it gives correct result? start from separate sq1 execution, check, if correct then execute sq2 and check again, and finally check the whole query). If it is correct then try to convert it to Laravel form.