OrderBy on Laravel polymorph one-to-one relationship - php

Question

I have problem to sort results by polymorph's table relationship.
Tried many ways, but results does not sort.
I have looked in many threads, and final result code that I have tried looks like this:
return \App\Models\Advert::with(['advertable' => function ($query) {
$query->orderBy('rooms', 'DESC');
}])->get();
I want to sort all rows in "adverts" table by relationship's "room" column, but nothing happens.
My tables structure is:
Laravel models looks like this:
<?php
// Main "adverts" polymorph table with advertable_id and advertable_type
class Advert extends \Illuminate\Database\Eloquent\Model
{
/**
* #return \Illuminate\Database\Eloquent\Relations\MorphTo
*/
public function advertable()
{
return $this->morphTo();
}
}
// "advert_flats" table
class Flat extends \Illuminate\Database\Eloquent\Model
{
/**
* #return \Illuminate\Database\Eloquent\Relations\MorphOne
*/
public function advert()
{
return $this->morphOne(\App\Models\Advert::class, 'advertable');
}
}
// "advert_homes" table
class Home extends \Illuminate\Database\Eloquent\Model
{
/**
* #return \Illuminate\Database\Eloquent\Relations\MorphOne
*/
public function advert()
{
return $this->morphOne(\App\Models\Advert::class, 'advertable');
}
}
UPDATE
If I dump SQL, then I see that this code does not event run into relationship
select * from `adverts` where `category_id` = 2 and `adverts`.`deleted_at` is null
Also I have tried to change whereHas function to work with polymorph relationships, as Laravel does not support whereHas with polymorph relations.
I have ran this code
return $model->whereHas('advertable', function ($q) {
$q->orderBy('rooms', 'DESC');
}, '>=', 1, ['\App\Models\Flat']);
But it also does not sort results.
I had to change Laravel builder to add support for polymorph tables.
UPDATE 2
I have resolved issue and implemented code by using example provided by #Sturm answer, after applying SortBy / SortByDesc I'm manually building LengthAwarePaginator.
But could this issue be resolved using Builder class, before calling ->get() method on my query ?

Answer 1

$adverts = \App\Models\Advert::query()->select(
DB::raw('
adverts.*,
CASE
WHEN adverts.advertable_type like(\'%Flat\') THEN advert_flats.rooms
WHEN adverts.advertable_type like(\'%Home\') THEN advert_homes.rooms
END
as rooms
')
)->leftJoin(
"advert_flats",
function ($join) {
/** #var \Illuminate\Database\Query\JoinClause $join */
$join->on('adverts.advertable_id', '=', "advert_flats.id")
->where('adverts.advertable_type', 'like', '%Flat');
}
)->leftJoin(
"advert_homes",
function ($join) {
/** #var \Illuminate\Database\Query\JoinClause $join */
$join->on('adverts.advertable_id', '=', "advert_homes.id")
->where('adverts.advertable_type', 'like', '%Home');
}
)->orderBy('rooms', 'ASC')->get();

Answer 2

Here's something that will get you running, although I'll look for a moment more to see if there's a way to do it from Builder.
$sorted = $adverts->sortBy(function ($val, $key) {
return $val->advertable->rooms;
}