我想在my index.php中调用导航之前将值发送到导航文件
索引.php

<?php
session_start();
$bookPage = 115;

//Sending bookpage value to navigation.php
$_SESSION['bookpage'] = $bookPage;

// Here I am including the value in navigation
include 'includes/navigation.php';

// Here I am expecting output from navigation $bookPage = 115 and relative query results

?>

导航.php

<?php
 $bookPage = $_SESSION['bookpage'];
 $sql2 = "SELECT * FROM page_categories WHERE book_page='$bookPage'";
 $pquery = $db->query($sql2);
?>

注意：如果我使用$sql2=“select*from page\u categories where book\u page='115'”；在navigation.php中，一切正常。
我没有把navigation.php放在index.php的顶部，因为那样我就不会得到结果，所以我试着这样做，但仍然不起作用。