how to save variables after using header function php - php

Question

After i submit a form and save the info to a database i use the header function to redirect to a more user friendly url but the variable $checkError is not saving, it gets reset after the header redirect. How can i save the variable even if the page gets refreshed?
if(isset($_GET['submit'])){
// get the post records <<
$id = '2';
$title = $_GET['title'];
$link = $_GET['link'];
// database connection
$con = mysqli_connect("localhost", "user", "password", "db_test");
$sql = "INSERT INTO test (id, title, link)
VALUES ($id, '$title', '$link')";
$rs = mysqli_query($con, $sql);
if($rs){
$checkError = '<div class="success">Success!</div>';
}else{
$checkError = '<div class="error">Not working!</div>';
}
mysqli_close($con);
//redirect to user friendly url
header("Location: /index.php?id={$id}");
}

Answer 1

You can write this to session data and recall it later, as one potential solution.
Modify/add in your example code block:
session_start();
if($rs){
$_SESSION['checkData'] = '<div class="success">Success!</div>';
}else{
$_SESSION['checkData'] = '<div class="error">Not working!</div>';
}
header("Location: /index.php?id={$id}");
And back on index.php, you would need to add/modify:
session_start();
if( isset( $_SESSION['checkData'] ) ){ // check whether it's set
echo $_SESSION['checkData']; // output variable
unset( $_SESSION['checkData']; // reset variable
}

Answer 2

You can use $GLOBALS OR $_SESSION as an array for $GLOBALS more details click here
you can use it as the below code in your header file
set value in $GLOBALS
$GLOBALS['checkError'] = '<div class="success">Success!</div>';
get value from $GLOBALS
echo $GLOBALS['checkError'];

Answer 3

Another way, very easy to implement is to skip $checkError variable and redirect user to a specific page:
// ...
$rs = mysqli_query($con, $sql);
mysqli_close($con);
$page = $rs ? 'success' : 'failure';
header("Location: /{$page}.php?id={$id}");

Answer 4

You have to store your data in cookies or sessions before the redirect.
A session is also used to store data, but I suggest you store data in cookies because the session stores data on the server-side, creating performance issues, whereas cookie stores data on the client-side.
You can check the critical difference of Cookie and Session
first.php
<?php
if($rs){
setcookie('checkError', '<div class="success">Success!</div>');
}else{
setcookie('checkError', '<div class="error">Not working!</div>');
}
?>
second.php
<?php
if(!isset($_COOKIE['checkError'])) {
echo $_COOKIE['checkError'];
}
?>
I hope this is helpful to you.