uts atol

<?php
  $host='localhost';
  $user='root';
  $pass='';
  $db='uts_atol';

  class diskon
  {
    var $hasil = 0;

    function set_diskon($kodebarang,$harga)
    {

      $diskon = array('A','B','C','D');
      $kodediskon = substr($kodebarang,0,1);
      if($diskon[0]==$kodediskon) { $hasil = $harga*0.05; }
      else if($diskon[1]==$kodediskon) {$hasil = $harga*0.1;}
      else if($diskon[2]==$kodediskon) {$hasil =$harga*0.15;}
      else if($diskon[3]==$kodediskon) {$hasil=$harga*0.2;}

      $this->hasil=$hasil;
    }

    function get_diskon()
    {
      return $this->hasil;
    }
  }


class jual
{
  var $harga=0;

  function set_jual($harga,$diskon)
  {
    $harga-=$diskon;

    $this->harga=$harga;
  }

  function get_jual()
  {
    return $this->harga;
  }
}

class subtotal
{
  var $total=0;

  function set_total($hargajual,$qty)
  {
    $total = $hargajual*$qty;

    $this->total=$total;
  }

  function get_total()
  {
    return $this->total;
  }
}

  $conn = mysqli_connect($host,$user,$pass,$db);

  if(!$conn)
  {
    die('Gagal terhubung ke MYSQL :'.mysqli_connect_error());
  }

    echo '<h1>DATA BARANG</h1>';
    echo '<form action="baru.php" method="POST">
          <input type="submit" name="tombol1" value="Terurut Kode Barang">
          <input type="submit" name="tombol2" value="Terurut Nama Barang">
          <input type="submit" name="tombol3" value="Terurut Harga dari Teramahal">
          </form>';



  $sql1 = 'SELECT penjualan.tgltransaksi,penjualan.kodebarang,barang.namabarang,barang.harga,penjualan.qty
  FROM penjualan INNER JOIN barang ON penjualan.kodebarang=barang.kodebarang ORDER BY kodebarang asc';
  $sql2 = 'SELECT penjualan.tgltransaksi,penjualan.kodebarang,barang.namabarang,barang.harga,penjualan.qty
  FROM penjualan INNER JOIN barang ON penjualan.kodebarang=barang.kodebarang ORDER BY namabarang asc';
  $sql3 = 'SELECT penjualan.tgltransaksi,penjualan.kodebarang,barang.namabarang,barang.harga,penjualan.qty
  FROM penjualan INNER JOIN barang ON penjualan.kodebarang=barang.kodebarang ORDER BY harga asc';
  $hasil = $sql2;

  if (isset($_POST["tombol1"])) {
      $hasil = $sql1;
  }
  else if (isset($_POST["tombol2"])) {
      $hasil = $sql2;
  }
  else if (isset($_POST["tombol3"])){
      $hasil = $sql3;
  }

$query = mysqli_query($conn,$hasil);

  if(!$query)
  {
    die("SQL  Error :".mysqli_error());
  }

  echo '<table border=1>
          <thead>
            <tr>
            <th>TGL TRANSAKSI</th>
            <th>KODE BARANG</th>
            <th>NAMA BARANG</th>
            <th>HARGA</th>
            <th>DISKON</th>
            <th>HARGA JUAL</th>
            <th>QTY</th>
            <th>SUB TOTAL</th>
            </tr>
          </thead>
          <tbody>';
$total1=0;
$total2=0;
while($row=mysqli_fetch_array($query))
{
  $diskon = new diskon();
  $diskon->set_diskon($row['kodebarang'],$row['harga']);

  $jual=new jual();
  $jual->set_jual($row['harga'],$diskon->get_diskon());

  $subtotal=new subtotal();
  $subtotal->set_total($jual->get_jual(),$row['qty']);

  echo '  <tr>
            <td>'.$row['tgltransaksi'].'</td>
            <td>'.$row['kodebarang'].'</td>
            <td>'.$row['namabarang'].'</td>
            <td>'.number_format($row['harga'],0,',','.').'</td>
            <td>'.number_format($diskon->get_diskon(),0,',','.').'</td>
            <td>'.number_format($jual->get_jual(),0,',','.').'</td>
            <td>'.$row['qty'].'</td>
            <td>'.number_format($subtotal->get_total(),0,',','.').'</td>
          </tr>
  ';
          $total1+=$row['qty'];
          $total2+=$subtotal->get_total();
}

  echo '  <tr>
            <td colspan="6">TOTAL</td>
            <td>'.$total1.'</td>
            <td>'.number_format($total2,0,',','.').'</td>
          </tr>
  ';

echo '    </tbody>
        </table>
        ';

 ?>