Updating Pivot table in laravel - php

Question

i have services and items table. i have the pivot table as service_item. I am able to store data into my pivot table however i can't get the right syntax to update the pivot table. My code stores a new data when i try to update an existing data.
PS: My code although is able to edit the client's name but not the items that the client bought earlier.
I want to be able to update the item_id and quantity
service_item - pivot.
service_id
item_id
qty
Controller
public function store(Request $request)
{
$service = new Service(array(
'id' => $service_no,
));
$service->save();
$selectedItems = [];
foreach($request->get('item_id') as $key => $id) {
$selectedItems[$id] = ['qty' => $request->get('quantity')[$key]];
}
$service->items()->attach($selectedItems);
}
public function update($id, Request $request)
{
$service = Service::findOrFail($id);
$service->clients->name = $request->get('name');
$service->clients->save();
$selectedItems = [];
foreach($request->get('item_id') as $key => $id) {
$selectedItems[$id] = ['qty' => $request->get('quantity')[$key]];
}
$service->items()->attach($selectedItems);
}

Answer 1

Okay after researching, i was able to solve this using updateExistingPivot
public function update($id, Request $request)
{
$service = Service::findOrFail($id);
$service->clients->name = $request->get('name');
$service->clients->save();
$selectedItems = [];
foreach($request->get('item_id') as $key => $id) {
$selectedItems[$id] = ['qty' => $request->get('quantity')[$key]];
}
$service->items()->updateExistingPivot($item_id, ['quantity' => selectedItems], false);
}