Laravel custom store mthod not working properly

I am intergrating paypal payment gateway on my application, before user first leave my site for paypal, I saved all the necessary information, and set payment_status to be 0, when user returns, if payment is sucessful, it returns to a new page where it gets the paymentId, and payerID, plus sets the paymentstatus to 1.

the thing is that if i set the database value for paymentID and PaymentId to null, it doesnt save.

if i dont set it to anything i.e leave it blank, it would save, but retruns an error:

Integrity constraint violation: 1048 Column 'PayerID' cannot be null (SQL: update `paypal_officers` set `paymentId` = , `PayerID` = , `updated_at` = 2018-07-15 07:29:21 where `id` = 1)

i cant seem to figure out what the problem is.

Here is the method that does the saving.

public function getPaymentStatus(Input $input)
    {
        /** Get the payment ID before session clear **/
        $payment_id = Session::get('paypal_payment_id');


            $insert_the_user_id = PaypalOfficer::findorFail(\session()->get('receivers_main_info_id'));
        $insert_the_user_id->update([
            'paymentId' => Input::get('paymentId'),
        'PayerID' => Input::get('PayerID'),
        'payment_status' => 1,

        ]);
            $insert_the_user_id->save();

                /** clear the session payment ID **/
                Session::forget('paypal_payment_id');
                if (empty(Input::get('PayerID')) || empty(Input::get('token'))) {
                    \Session::put('error', 'Payment failed');
                    return Redirect::to('account/send-money/paypal/send')->with('payer_id', $payment_id);;
                }
                $payment = Payment::get($payment_id, $this->_api_context);
                $execution = new PaymentExecution();
                $execution->setPayerId(Input::get('PayerID'));
                /**Execute the payment **/
                $result = $payment->execute($execution, $this->_api_context);
                if ($result->getState() == 'approved') {
                    \Session::put('success', 'Payment success');
                    return Redirect::to('account/send-money/paypal/stagged/paypal')->with('payer_id', $result);
                }
                \Session::put('error', 'Payment failed');
                return Redirect::to('account/send-money/paypal/send');

}

My Model

namespace App;

use Illuminate\Database\Eloquent\Model;

class PaypalOfficer extends Model
{
    protected $fillable = [
        'payment_status',
        'paymentId',
        'PayerID',
        'user_id',
        'amount',
        'destination_account_number',
        'destination_account_name',
        'destination_bank_name',
        'destination_phone_number',
        'destination_country',
        'destination_state',
        'currency_symbol',
        'receivers_name',
    ];
    //
    public function user(){
        return $this->belongsTo(User::class);
    }
}

Please what must i be missing in the code , anybody please!

via Chebli Mohamed