MySQL update DATETIME to NOW() using PHP

Question

This all worked before I added the section to update "last_update".

if((time() - $last_update) > 7200){
$sql = $dbh->prepare("UPDATE item_list SET quantity=:quantity, price=:price, last_update=:now WHERE item_name=:itemname");
                $sql->bindParam(':quantity', $json->volume);
                $sql->bindParam(':price', $json->lowest_price);
                $sql->bindParam(':itemname', $row['Item_Name']);
                $sql->bindParam(':now', "NOW()");  //This doesn't work
                $sql->execute();
}

When this is called I want to make last_update the date and time now. In the database it is currently a DATETIME, and when I last_update I origianly set them to NOW();

Doing this I get the error Fatal error: Cannot pass parameter 2 by reference in.... Directory

I know it expects a variable, I'm not sure how to fix it though. I tried setting

$now = "NOW()"; $sql->bindParam(':now', $now);

No prevail. Any help?

Answer 1

Why you need to bind, just put NOW() directly

$sql = $dbh->prepare("UPDATE item_list SET quantity=:quantity, price=:price, last_update=now() WHERE item_name=:itemname");

Answer 2

If your last_update column is looking for a UNIX timestamp, then do :

$now = time(); 
$sql->bindParam(':now', $now);

If it's after a different time format, use date(), and the relevant formatting it has to set the date and time