extract with EXTR_PREFIX_ALL does not give me variables

I’m trying use extract() to create prefixed variables. However, the variable I expect is not being created, and I get an undefined variable warning.

Here’s my code:

<?php
    $my_user_id = 1;


    $stmt = $mysqli->prepare("SELECT id, email FROM users_index WHERE user_id=?"); 
    $stmt->bind_param("i", $my_user_id);
    $stmt->execute();
    $result = $stmt->get_result();
    $row = $result->fetch_assoc();
    $stmt->close();
    if (!$row) {
        echo "<p>There was no rows returned for your user session.</p>"; die;
    }
    extract($row, EXTR_PREFIX_ALL, 'sql_my_');

    if (empty($sql_my_id)) {
        echo "
        <p>PHP Error: The variable is blank. row['id']={$row['id']} sql_my_id=$sql_my_id.</p>
        <pre>";
        print_r($row);
        echo "</pre>";
        die;
    }

Output:

Warning: Undefined variable $sql_my_id in C:Apache24htdocswebsitetest.php

PHP Error: The variable is blank. row[‘id’]=1 sql_my_id=.

Array
(
[id] => 1
[email] => [email protected]
)

Problem:
I expected extract($row, EXTR_PREFIX_ALL, 'sql_my_') to create $sql_my_id and $sql_my_email, but $sql_my_id is not defined.

What I’ve tried:

• Using EXTR_PREFIX_ALL with a prefix.
• Checking if $row is empty before extracting.

Why isn’t $sql_my_id being created by extract()? How can I correctly create prefixed variables from my associative array?