Sums data from an array that has the same id - php

Question

I have a query about this project that I am doing, I make a query to my two tables and the data that I call in this case is a quantity number for both, the data displayed is the one that has the same id for both tables.
The problem occurs when I pass two identifiers and to those two identifiers I want to add their current amount with the amount obtained from the other table
In general, what I want to do is add the amounts obtained, this is my code that I am working with, I would really appreciate if you can help me solve it or guide me.
$id_servis = [1077,1078];
$sum_quantity_add = Servis_tareas::where('servis_id',$id_servis)->get();
foreach($sum_quantity_add as $sum_add){
$quantity_two[] = $sum_add->quantity;
}
$quantity_actual = Servis::wherein('id',$id_servis)->get();
foreach($quantity_actual as $quantity_act){
$quantity_one[] = $quantity_act->quantity_final;
}
dd($id_servicios,$quantity_one, $quantity_two);
//ERROR
$total[] = $quantity_one + $quantity_two;
//ERROR
if(is_numeric($total) < 0 ){
Servis::wherein('id',$id_servis)->update(['quantity_final' => 0]);
}else{
Servis::wherein('id',$id_servis)->update(['quantity_final' => $total]);
}

Answer 1

In MySql/SQL there is SUM query which handles the addition and they are called Aggregation Functions, and in Laravel there is a Eloquent equivalent of these Laravel Aggregates, using these methods you will be able to count, max, min, avg on the query end rather than in the PHP end.
So, your code will look like
$id_servis = [1077, 1078];
$sum_quantity_add = Servis_tareas::where('servis_id', $id_servis)->SUM('quantity');
$quantity_actual = Servis::wherein('id', $id_servis)->SUM('quantity_final');
$total = $sum_quantity_add + $quantity_actual;
What you are trying is treating array as numeric value and adding it, which is wrong, + operator behaves totally different while you are using with array, it merges the two array, it is different than array_merge too, so i recommend giving this answer a read + operator for array in PHP
UPDATED:
I still don't understand if you want to replace with the SUM from Servis_tareas in the Servis Table or sum the each others quantity and save it, Code below sum the data from both table and save it.
$id_servis = [1077, 1078];
$servisTareas = Servis_tareas::selectRaw("SUM(`quantity`) as total, `servis_id` ")
->where('servis_id', $id_servis)
->groupBy('servis_id')
->having('total', '>', 0)
->get();
$foundId = [];
$servisTotal = Servis::query()->whereIn('id', $id_servis)->pluck('quantity_final', 'id')->toArray();
foreach ($servisTareas as $servisTarea) {
$foundId[] = $servisTarea->servis_id;
$total = $servisTarea->total + ($servisTotal[$servisTarea->servis_id] ?? 0)
Servis::where('id', $servisTarea->servis_id)->update(['quantity' => $total]);
}
if (!empty($foundId)) {
Servis::whereNotIn('id', $foundId)->update(['quantity' => 0]);
}