Php code for inventory system in updating item quantity

[cotton]

recently,im developing an inventory system. the problem is i still dont know how to automatically update the quantity in the stock after the user take the items and how to add the item to the cart as in a shopping cart system. pls help..im using easyphp and i do not use class and function in my system.help me pls...

this is the sample of my code:
<table width="80%" border="1" align="center" cellpadding="0" cellspacing="1" bordercolor="#CCCCCC">
<tr>
<td width="18%" bgcolor="#E0E2EB"><div align="left">Description : </div></td>
<td width="82%"><? echo $row['description']; ?></td>
</tr>
<tr>
<td bgcolor="#E0E2EB"><div align="left">Item Code : </div></td>
<td><? echo $row['item_code']; ?></td>
</tr>
<tr>
<td bgcolor="#E0E2EB"><div align="left">Category : </div></td>
<td><? echo $row['category']; ?></td>
</tr>
<tr>
<td bgcolor="#E0E2EB"><div align="left">Current quantity : </div></td>
<td><? echo $row['quantity']; ?></td>
</tr>
<tr>

<td bgcolor="#E0E2EB">Required quantity : </td>
<td><input type="text" name="quantity" value="<? echo $row['quantity']; ?>">
<input type="hidden" name="id" value="<? echo $row['quantity']; ?>"></td>

</tr>



</table>


thnx in advance..

i stored the cart in the database..

Anyone..help me pls..i need the code so badly.

 

[AzN]

You can add upon checkout.
Here's just a sample of what you want to use...

$item = $_GET['item']

$result = mysql_query("SELECT * FROM inventory
 WHERE item='$item'") or die(mysql_error());  

$row = mysql_fetch_array( $result );

$count = $row['count'] - 1;

$result = mysql_query("UPDATE inventory SET count='$count' WHERE item='$item'") 
or die(mysql_error());

 

[cotton]

thank u very much!! i will try that on..

 

[cotton]

how to show the item in the cart?

 

[cef]

Ack! Never trust user input (e.g., $_POST and $_GET variables). The above code is open to a sql injection.

Replace

$item = $_GET['item'];

with

$item = mysql_real_escape_string($_GET['item']);

Also, you might want to check if the item actually exists, and if you have any in stock:

$row = mysql_fetch_array( $result );

if ($row === false)
{
        echo 'this item does not exist!';
        return; // or whatever you need to do
}
else
{
        if ($row['count']  == 0)
        {
             echo 'sorry, none in stock.';
             return; // or whatever you need to do
        }

        // if you got here you have stock on hand, so continue
        $count = $row['count'] - 1;
        // etc...
}

Just a rough draft, but you get the idea.