PHP not seeing function?

Question

PHP

Good day! There is such a code, when I put it in a function (function), then this code, when the function is declared, stops working. Maybe someone knows what the problem is. Thank you.

<?php
                $result_set = mysqli_query($connect, "SELECT * FROM `newCity`");

                while ($row = $result_set->fetch_assoc()) {
                $result_set = mysqli_query($connect, "SELECT * FROM `new_test_table` WHERE `newCity` = '".$row["city"]."'");

                while ($row_1 = $result_set->fetch_assoc()) {
                  echo "<option>".$row_1["newDistrict"]."</option>";
                  }
                }
               ?>

Answer 1

The internal vanga says that the problem is in the visibility of variables in general and $connect in particular.
error output? no, have not heard.

Answer 2

The variable
in the function is probably not declared.
And yes, I advise you to use ReadBeanPHP