Simple Transfer Snippets in laravel

simple_transfer_snippets_in_laravel.php

//transfer\routes\api.php
<?php

use Illuminate\Http\Request;

use Illuminate\Database\Eloquent\Model;

class Balance extends Model{
    protected $fillable = ['account_nr','balance'];
}

class Transaction extends Model{
    protected $fillable = ['reference','amount','account_nr'];
}

// Balance::create([
//     'account_nr'=>'1234567890',
//     'balance'=>'27654967'
// ]);

// Balance::create([
//     'account_nr'=>'0987654321',
//     'balance'=>'2653965'
// ]);

Route::post('/transfer',function(Request $request){
    DB::transaction(function ()use($request) {
        $sender = Balance::where('account_nr',$request->from)->first();
        $sender->balance = $sender->balance - $request->amount;
        $sender->save();
        
        $receiver = Balance::where('account_nr',$request->to)->first();
        $receiver->balance = $receiver->balance - $request->amount;
        $receiver->save();

        Transaction::create([
            'reference'=>"receive_from_{$request->from}_".md5(time()),
            'amount'=>$request->amount,
            'account_nr'=>$request->to
        ]);

        Transaction::create([
            'reference'=>"send_to_{$request->to}_".md5(time()),
            'amount'=>$request->amount,
            'account_nr'=>$request->from
        ]);
    }); 

    return response()->json(['sucess'=>true]);
})->name('transfer');


//transfer\database\migrations\2020_07_24_213850_create_transaction_table.php
<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateTransactionTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('transactions', function (Blueprint $table) {
            $table->string('reference')->unique();
            $table->string('amount');
            $table->string('account_nr');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('transactions');
    }
}

//transfer\database\migrations\2020_07_24_213444_create_balance_table.php
<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateBalanceTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('balances', function (Blueprint $table) {
            $table->string('account_nr')->unique();
            $table->string('balance');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('balances');
    }
}

//Test
//curl -XPOST -d"from=1234567890&to=0987654321&amount=4000" http://localhost:9000/api/transfer