Laravel ManyToMany relations where to save item total?

Question

Need advice what is best practice for Many To Many relations where to save item total column? For ex. I have Users and Inventory Table, they are connected by pivot table and in pivot table i also have column total of attached Inventory. Is it correct way or can someone advice me which will be best way for it?

DB Structure

Answer 1

I may suggest :

1) Make the pair of foreign keys unique (user_id, inventory_id) to prevent duplicates

2) Make a seperate model for you pivot table : App\InventoryUser

3) Make use of updateOrCreate Laravel Elequent function

According to Elequent Docs

updateOrCreate will update an existing model or create a new model if none exists

E.g

$oldTotal = InventoryUser::where(['user_id' => 'x', 'inventory_id' => 'y'])->select('total') ?? 0;
$inventoryUser = InventoryUser::updateOrCreate(
    ['user_id' => 'x', 'inventory_id' => 'y'],
    ['total' => $oldTotal+1]
);

Or even better

$inventoryUser = InventoryUser::updateOrCreate(
        ['user_id' => 'x', 'inventory_id' => 'y']
)->increment('total'); // You must Set DEFAULT value to (0) for total column in your database