update session

[pFC]

I test to create a simple shopping site and getting headache to update a previous session. Here the codes.

 

index.php

 

<ul>
<?php while($product = $db->fetch($qb)) { ?>
<li style="float:left; width:200px; list-style:none;">
<strong><?php echo $product['title'];?></strong>
<form action="update.php" method="post">
<input type="hidden" name="item-id[]" value="<?php echo $product['id'];?>"  />
<input type="hidden" name="item-name[]" value="<?php echo $product['title'];?>"  />

<select name="item-qty[]" onchange="this.form.submit()">
<?php for($i=0;$i<11;$i++) { ?>
<option<?php if($_SESSION['order'][''.$product['id'].'']['item-qty'] == $i){ ?> selected="selected"<? }?> value="<?php echo $i;?>"><?php echo $i; ?></option>
<?php } ?>
</select>

<?php if($_SESSION['order'][$product['id']]['item-price'] == '') { echo '$ 0'; unset($_SESSION['order'][$product['id']]); } else {  echo '$ '.$_SESSION['order'][$product['id']]['item-price']; }?>
<?php if  (sizeof($_SESSION['order']) < 1) { unset($_SESSION['order'],$_SESSION['count']); } ?>

</form>
</li>
<?php $j++; } ?>
</ul>

 

update.php

<?php
  $qty = $_POST['item-qty'];
  $id = $_POST['item-id'];
  $i = count($q);
  $n = 0;
  
  while ($n < $i) {
      $select = 'SELECT * FROM price';
      $query = $db->rq($select);
      $price = $db->fetch($query);
      $get = $price['normal_price'];
      $price = $get * $_POST['item-qty'][$n];
      $_SESSION['order'][$_POST['item-id'][$n]] = array("item-id" => $_POST['item-id'][$n], "item-qty" => $_POST['item-qty'][$n], "item-name" => $_POST['item-name'][$n], "item-price" => $price, );
      
      $qty_sum = 0;
      foreach ($_SESSION['order'] as $key => $value) {
          $qty_sum += $value['item-qty'];
          $_SESSION['count'] = $qty_sum;
      }
      
      if ($qty_sum >= 3) {
          $select = 'SELECT * FROM price';
          $query = $db->rq($select);
          $price = $db->fetch($query);
          $get = $price['member_price'];
          $price = $get * $_POST['item-qty'][$n];
          $_SESSION['order'][$_POST['item-id'][$n]] = array("item-id" => $_POST['item-id'][$n], "item-qty" => $_POST['item-qty'][$n], "item-name" => $_POST['item-name'][$n], "item-price" => $price, );
      }
      
      $n++;
      header('location:index.php');
      exit();
  }
?>

 

1. Here have a different price. Normal Price and Member Price

2. If total of quantity <= 2 price per quantity should be $200 - Normal Price

3. If total of quantity >= 3 price per quantity should be $150 - Member Price

 

Question

1. How to update current session price to be $150/per qty if buyer select total of quantity more than 3 and back to normal price if qty below than 3.

2. Now it only working on last item. How to fix it?

 

More clearly take a look my demo page here