laravel sum of property in parent *and* children models? - laravel

Question

I have Places that get appear in Timelines. These places can be grouped: a parent Place can have children Places (only one level deep).
Would like to lazy load the Places including visit counts of that Place and its children, and order by total count.
It's too many places to get 'em all up front and do the sum and sort afterwards.
Simplified example of the result I am trying to get:
- place B - visits 5, visits children 6, total visits 11
- place B.1 - visits 2
- place B.2 - visits 4
- place A - visits 5, visits children 0, total visits 5
- place C - visits 1, visits children 2, total visits 3
- place C.1 - visits 2
With the code below I get all of that but the "total visits".
I am using straightforward relationships for the Place model:
public function children(){
return $this->hasMany(Place::class, 'parent_id');
}
public function visits(){
return $this->hasMany(Timeline::class);
}
public function visitsChildren(){
return $this->hasManyThrough(
Timeline::class, // the end result
Place::class, // going through this one
'parent_id', // foreign key on Place (child)
'place_id', // foreign key on Timeline
'id', // local key on Place (parent)
'id' // local key on Place (child)
);
}
I can get the visit count for that Place and the children and their visit counts.
\App\Models\Place::where(...)
->withCount('visits', 'visitsChildren')
->with('children', fn($q) => $q->withCount('visits'))
->orderByDesc('visits_count')
->get()
But how to add them up and sort by the total (without eager loading)?
I.e. can I "merge" visits and visitsChildren?
Tried this but that does not work because column visits_count and visits_children_count are (understandably) not available at that level:
...
->select(DB::raw('visits_count + visits_children_count as visits_including_children_count'))
->get()
Update: added the relationship for visitsChildren and the DB::raw attempt.

Answer 1

You can use map() and sum() methods of laravel collection and solve this
$result = \App\Models\Place::where(...)
->withCount('visits')
->with('children', fn($q) => $q->withCount('visits'))
->orderByDesc('visits_count')
->get();
$count = $result->map(function ($item) {
$children_count = $item->children->sum(function ($child) {
return $child->visits_count ?? 0;
});
return $children_count + $item->visits_count;
});
dd($count);