Data not updating in PHP mysql - php

Question

Message show:
Product not updated!
Not updating through form. Rest of the code is working fine. Database is working fine. I think problem is in update query.
HTML form is in product.php and Controller is in product-controller.php and function code is in admin-model.php.
Select insert and delete query is working but update query is not working I don't understand why.
HTML Form
<form action="product-controller.php?type=update" method="post">
<input type="hidden" value="<?php echo $r["productid"]; ?>" name="productID" id="productID"/>
<div>
<label>Product Name</label>
<input type="text" value="<?php echo $r["product_name"]; ?>" name="productName" placeholder="Product Name">
</div>
<div>
<label>Product Price</label>
<input type="number" value="<?php echo $r["product_price"]; ?>" name="productPrice" placeholder="Product Price">
</div>
<div>
<label>Product Quantity</label>
<input type="number" value="<?php echo $r["product_quantity"]; ?>" name="productQuantity" placeholder="Product Quantity">
</div>
<div>
<label>Product Description</label>
<textarea name="productDesc"><?php echo $r["product_description"]; ?></textarea>
</div>
<div>
<button type="submit">Update Product</button>
</div>
</form>
Controller
<?php
include("admin-model.php");
if(isset($_GET["type"]))
{
$dbobj=new AdminModel;
if($_GET["type"]=="add")
{
$name=$_POST["productName"];
$price=$_POST["productPrice"];
$quantity=$_POST["productQuanity"];
$desc=$_POST["productDesc"];
$res=$dbobj->addProduct($name, $price, $quantity, $desc);
if($res>0)
{
header("Location: product.php?msg=sucess");
}
else
{
header("Location: product.php?msg=fail");
}
}
else if($_GET["type"]=="update")
{
$id=$_POST["productID"];
$name=$_POST["productName"];
$price=$_POST["productPrice"];
$quantity=$_POST["productQuantity"];
$desc=$_POST["productDesc"];
$res=$dbobj->updateProduct($id, $name, $price, $quantity, $desc);
if($res>0)
{
header("Location: product.php?msg=upsucess");
}
else
{
header("Location: product.php?msg=upfail");
}
}
else if($_GET["type"]=="del")
{
$id=$_GET["productID"];
$res=$dbobj->deleteProduct($id);
if($res>0)
{
header("Location: product.php?msg=delsucess");
}
else
{
header("Location: product.php?msg=delfail");
}
}
}
else
{
header("Location: product.php");
}
?>
Function Code
<?php
class AdminModel
{
var $con, $com;
var $res;
public function __construct()
{
$this->con=mysql_connect("localhost", "root", "");
mysql_select_db("mywebsitedb");
}
public function updateProduct($id, $name, $price, $quantity, $desc)
{
$this->com=mysql_query("update product set product_name='$name', product_price='$price', product_quantity='$quantity', product_description='$desc', where productid='$id'", $this->con);
return $this->com;
}

Answer 1

Please correct your update query as follows:
$this->com=mysql_query("update product set product_name='$name', product_price='$price', product_quantity='$quantity', product_description='$desc' where productid='$id'", $this->con);

Answer 2

This Query SQL is wrong syntax :
update product set product_name='$name', product_price='$price',
product_quantity='$quantity', product_description='$desc', where productid='$id'
-->
update product set product_name='$name', product_price='$price',
product_quantity='$quantity', product_description='$desc' where productid='$id'