Clone data from one to another database column in Laravel

Question

I have two columns quantity and remaining_quantity in my stock table. I wanted to copy same data from quantity to remaining_quantity while doing a create function. Is there any function in Laravel for that?

Answer 1

You can do that by creating an observer.

1- Create a folder called observers in you app folder.

2- Create a file named MyModelObserver.php for example StockObserver.php.

3- Prepare your class like the following:

<?php
namespace App\Observers;


class StockObserver
{
    //
}

Inside that class you can create creating, created, updated, updated, deleting, deleted, saving and saved methods. Which their jobs are obvious from their names. For more details see => https://laravel.com/docs/5.5/eloquent#events

For example the following code will do something everytime an object of Stock model is created.

<?php
namespace App\Observers;


use App\Stock;

class StockObserver
{
    public function created(Stock $stock)
    {
        $stock->remaining_quantity = $stock->quantity;
        $stock->save()
    }
}

But all these code won't be effective unless you observe that in the AppServiceProvide .. so in the boot method in AppServiceProvider write the following.

\App\Stock::observe(\App\Observers\StockObserver::class);

That's it .. Hope it helps.