insert and update row in mysql

[tobitimac]

how can i make this code to insert a single, multiple and update rows in the database. The code only insert new rows in the database.

 

if (($handle = fopen('inventorylist.csv', "r")) !== FALSE) {
    while (($data = fgetcsv($handle, 100000, ",")) !== FALSE) {
        $num = count($data);
      

                  $sql="INSERT into inventory(itemNumber,itemDesc,quantityHand,category,Whse) values('$data[0]','$data[1]','$data[2]','$data[3]','$data[4]')";

                    mysql_query($sql) or die(mysql_error());

       
    }
    fclose($handle);

        }