If new row exist than display number of new rows

Question

I have a problem and i dont know how to do this. I tryed to find information about that maybe 2-3 hours.

I have this code:

<?php
$stmt = $db->query("select count(id) from $medis order by zinutes")->fetchColumn();
echo $stmt;
?>

Explanation:

At the moment, in "zinutes" row, there is 10 records, and this code displays number "10".

Question:

If i am inserting new record, i need to display another number with new record inserted. How can i do this properply? And is this even possible without jquery? I am not good at php.

Thanks for any answers!