Loop through array, and change item details with adding counter

Question

I am new in Laraver, I am using Eloqunet model... deleteItem function, delete item with offer_in and nbr...When delete item I want to add a new nbr from each item with equal offer_id, starting from 1. I need to define counter = 1, and increase by 1 for every item.. I don't know how to write a for loop, or foreach loop, which pass through selected item, and change 'nbr' with the corresponding value of the counter?

my code is:

public function deleteItem(Request $request, $offer_id, $nbr) {
    $item = OfferItem::select('id', 'offer_id', 'nbr', 'product', 'quantity', 'item_price', 'item_tax', 'item_total')
                     ->where('offer_id', $offer_id)
                     ->where('nbr', $nbr)
                     ->first();
    $item->delete();
        
    //select new items for offer, after deleting item
    $items = OfferItem::select('id', 'offer_id', 'nbr', 'product', 'quantity', 'item_price', 'item_tax', 'item_total')
                      ->where('offer_id', $offer_id)
                      ->get();

    //todo

    return response()->json($item);
}

for example, i have 5 items for offer, nbr are 1,2,3,4,5. when I delete item with nbr 3 I want to ''reset'' nbr to be again 1,2,3,4.. I don'w want to have items for offer with nbr 1,2,4,5 when I delete item with nbr3 — Qli, Jul 28 '20 at 11:58
This is still not very clear to me. What is nbr? What does its schema look like? How exactly is it related to ```OfferItem```? — Kurt Friars, Jul 28 '20 at 12:00
hm, nbr is number of items..first item in list has nbr 1, second item in list has nbr 2... — Qli, Jul 28 '20 at 12:06

Kurt Friars · Answer 1 · 2020-07-28T12:08:59.370

You can achieve this purely in SQL like in these examples.

You can achieve what you want using Laravel by:

public function deleteItem(Request $request, $offer_id, $nbr) {
    OfferItem::query()
             ->where('offer_id', $offer_id)
             ->where('nbr', $nbr)
             ->delete();
        
    // Select new items for offer, after deleting item
    $items = OfferItem::where('offer_id', $offer_id)
                      ->where('nbr', '>', $nbr)
                      ->get()
                      ->sortBy('nbr')
                      ->map(function ($item) use ($nbr) {
                          $update = [
                              'id' => $item->id,
                              'nbr' => $nbr,
                          ];
                          
                          $nbr++;

                          return $update;
                      });

    OfferItem::query()->update($items);

    return response()->json($item); // It is not clear from your question what you
                                    // are trying to return here. Why would you
                                    // return a deleted item?
}

score 2 · Accepted Answer · answered Jul 28 '20 at 12:04

Using the Laravel collections, you can just loop the collection and set new count to nbr. Using $count as a reference for the closure, to make the logic work.

$int = 1;

$items->each(function (OfferItem $item) use (&$count) {
    $item->nbr = $count;
    $item->save();

    $count++;
});

Loop through array, and change item details with adding counter

2 Answers2