How do i change the URL id? - php

Question

Hi how do i change the URL id if the id is above max id in the db?
If i get the id from a database and use it in a read more button to make people read the data in a new page with the id as different url query?
--The real question
How do i make sure that if there only are 4 news in the db that if you write etc
newsTest.php?id=5 in the browser the browser will not execute or go back to max page?
//read more button
Læs mere
<?php
include_once 'includes/db.php';
$sql1 = "SELECT COUNT(id) AS total FROM rock_news ";
$result1 = $dbCon->query($sql1);
$row1 = $result1->fetch_assoc();
$total_pages = $row1["total"];
$thisVar = $_GET['id'];
if($total_pages >= $thisVar){
echo "alt er godt";
if(isset($_GET['id']) && !empty($_GET['id'])){
$id = $_GET['id'];
// mod sqlinjection
$id = $dbCon->real_escape_string($id);
$sql = " SELECT id, heading, subheading, description, created, author FROM rock_news WHERE id = " . $id ;
$result = $dbCon->query($sql);
if ($result->num_rows > 0) {
$row = $result->fetch_object();
$id = $row->id;
$heading = utf8_encode($row->heading);
$subheading = utf8_encode($row->subheading);
$description = utf8_encode($row->description);
$created = $row->created;
$author = utf8_encode($row->author);
$output .= $id . "<br>" . $heading . "<br>" . $description;
};
// udskriv output til bruger
echo $output;
};
} else {
$_GET['id'] = $total_pages ;
echo "nothing";
}
?>
I am very new to php

Answer 1

Check if total_pages is less than id then show show total_pages id.
<?php
include_once 'includes/db.php';
$sql1 = "SELECT COUNT(id) AS total FROM rock_news ";
$result1 = $dbCon->query($sql1);
$row1 = $result1->fetch_assoc();
if(isset($_GET['id']) && !empty($_GET['id'])){
$total_pages = $row1["total"];
$thisVar = $_GET['id'];
if($total_pages < $thisVar){
$thisVar=$total_pages
$id = $thisVar;
// mod sqlinjection
$id = $dbCon->real_escape_string($id);
$sql = " SELECT id, heading, subheading, description, created, author FROM rock_news WHERE id = " . $id ;