Php mariadb sum divided by if there is no value, can NAN, be shown as 0?

$selectTip = $pdo->query("SELECT * FROM `tips_rate`
                WHERE `tip_id` = "".$row["id"]."" "
              );
              $selecttotal = mysqli_num_rows($selectTip);
              $rate = $pdo->query("SELECT SUM(star) as startotal FROM `tips_rate`
                WHERE `tip_id` = "".$row["id"]."" "
              );
              $startotal = mysqli_fetch_array($rate);
              echo $startotal["startotal"]/$selecttotal;

when we echo the result of their division by
there is no value, he will see NAN.. Can you show me 0?

Mysqli mariadb php

Feb.26,2021

$num = $startotal ['startotal'] / $selecttotal;
echo is_nan ($num)? 0: $num;

Previous: .dispatch is not a function

Next: How to match floating-point exact 1 bits and integers using match

What is the principle of the relational number table? There is a query, but the query does not show?
assume that there is an item count table and use an item table when I want to make an item list I want to show an item table the behavior of an item table is to add this item to the goods store but I am shopping. How can I show it? I think of seve...

Mysql mysqli mariadb php php7

Mar.21,2021