updating mysql data using php with a drop down option - php

Question

I am trying to update my products table using a product form but it is throwing an error for an undefined variable here is my code for the productform.php
<?php
$ProductID= $_GET['ProductID'];
//Connect and select a database
mysql_connect ("localhost", "root", "");
mysql_select_db("supplierdetails");
{
$result = mysql_query("SELECT * FROM products WHERE ProductID=$ProductID");
while($row = mysql_fetch_array($result))
{
$ProductID= $_GET['ProductID'];
$ProdDesc = $row['ProdDesc'];
$SupplierID = $row['SupplierID'];
$Location = $row['Location'];
$Cost = $row['Cost'];
$Status = $row['Status'];
$MRL = $row['MRL'];
$ProductID = $row['ProductID'];
}
?>
//form
<form action="Edit_Prod.php" method="post">
<input type="hidden" name="ProductID" value="<?php echo $ProductID; ?>"/>
<label>Product Description:
<span class="small">Please enter a description for the product </span>
</label>
<input type="text" name="ProdDesc" value="<?php echo $ProdDesc ;?>" />
<label>Supplier ID
<span class="small">Please enter the Supplier ID</span>
</label>
<input type="text" name="SupplierID" value="<?php echo $SupplierID ;?>" />
<label>Bay Location:
<span class="small">Please select the bay location for this product </span>
</label>
<select name="Location" value="<?php echo $Location ;?>" />
<option>A1</option>
<option>A2</option>
<option>A3</option>
<option>A4</option>
<option>A5</option>
<option>B1</option>
<option>B2</option>
<option>B3</option>
<option>B4</option>
<option>B5</option>
<option>C1</option>
<option>C2</option>
<option>C3</option>
<option>C4</option>
<option>C5</option>
<option>D1</option>
<option>D2</option>
<option>D3</option>
<option>D4</option>
<option>D5</option>
<option>E1</option>
<option>E2</option>
<option>E3</option>
<option>E4</option>
<option>E5</option>
</select>
<label>Product Cost:
<span class="small">Please enter a new cost for the product (per roll) </span>
</label>
<input type="text" name="Cost" value="<?php echo $Cost ;?>" />
<label>Status:
<span class="small">Please select a status for the product </span>
</label>
<select name="Status" value="<?php echo $Status ;?>" />
<option>Live</option>
<option>Mature</option>
<option>Obsolete</option>
</select>
<label>MRL
<span class="small">Please enter a minimum re-order level for this product </span>
</label>
<input type="text" name="MRL" value="<?php echo $MRL ;?>" />
<input type="submit" value= "Edit Product Details"/>
Undefined variable all lines, do i have to do anything differently if using drop down areas*
*Edit_Prod.php*
<?php
$con = mysql_connect("localhost", "root", "");
mysql_select_db("supplierdetails");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
//Run a query
$ProductID = $_POST['ProductID'];
$result = mysql_query ("SELECT * FROM products WHERE Productid= '".$Productid."'") or die(mysql_error());
$row = mysql_fetch_array($result);
$ProdDesc = $_POST['ProdDesc'];
$SupplierID = $_POST['SupplierID'];
$Location = $_POST['Location'];
$Cost = $_POST['Cost'];
$Status = $_POST['Status'];
$MRL = $_POST['MRL'];
$Productid=$row['Productid'];
$query="UPDATE products SET ProdDesc='".$ProdDesc."', SupplierID='".$SupplierID."', Location='".$Location."', Cost='".$Cost."', Status='".$Status."', MRL='".$MRL."' WHERE ProductID='".$ProductID."'";
$result = mysql_query($query);
//Check whether the query was successful or not
if($result)
{
echo "Products Updated";
header ("Location: Products.php");
}
else
{
die ("Query failed");
}
?>

Answer 1

i think $row vairable is used to get values from database which you have missed
$productID= $_GET['productid'];
$records =mysql_query(" select * from tableName where productid=$productID");
$row=mysql_fetch_array($records);
then your code will work
$supplId= $row['supplId'];
...

Answer 2

Answering to your question "do i have to do anything differently if using drop down areas", of course you have to change it. Change:
<select name="Location" value="<?php echo $Location ;?>" />
<option>A1</option>
<option>A2</option>
<option>A3</option>
<option>A4</option>
<option>A5</option>
.
.
. . .. .
To:
<select name="Location" />
<option value="<?=$Location;?>" selected="selected" ></option>
<option>A1</option>
<option>A2</option>
<option>A3</option>
<option>A4</option>
<option>A5</option>
like that. I think you got the idea. You have to get value as an option under select. Try it. Good luck.