Value Replace in Database

$dbhost="localhost"; //name of the database host
$dbname="product"; // database name
$dbuser="root"; // database user
$dbpassword=""; // database password


$conn = mysql_connect("$dbhost", "$dbuser", "$dbpassword")
or die(mysql_error());

mysql_select_db("$dbname",$conn);
$sql="select * from product_list;" ;
$result = mysql_query($sql);

$i=0;
while ($item=mysql_fetch_array($result))
{
$sql_replace="update product_list set name='something' where id=$item[0]";

$result_replace = mysql_query($sql_replace);
$i++;
}
echo "Number of Record Update==".$i;

?>