How do i create pagination for my search results - php

Question

I'm trying to create pagination for my search results. I'm able to create a working pagination if I drop the search functionality (i.e by not including if (isset($_POST['submit-search'])) and LIKE %search%) but once I include these, as seen in the code beneath, I only get a blank page when I click the next page, like as if the sql terms isn't kept in memory.
<?php
if (isset($_POST['submit-search'])) {
$results_per_page = 2;
$search = mysqli_real_escape_string($conn, $_POST['search']);
$sql = "SELECT * FROM article WHERE a_title LIKE '%$search%' OR a_text LIKE '%$search%'";
$result = mysqli_query($conn, $sql);
$queryResult = mysqli_num_rows($result);
$number_of_pages = ceil($queryResult/$results_per_page);
// determine which page number visitor is currently on
if (!isset($_GET['page'])) {
$page = 1;
} else {
$page = $_GET['page'];
}
$this_page_first_result = ($page-1)*$results_per_page;
$sql = "SELECT * FROM article WHERE a_title LIKE '%$search%' OR a_text LIKE '%$search%'LIMIT ".$this_page_first_result.",".$results_per_page." ";
$result = mysqli_query($conn, $sql);
// echoing the search results
while ($row = mysqli_fetch_assoc($result)) {
echo "<h3>".$row['title']."</h3>
<p>".$row['text']."</p>";
}
// echoing the pagination
for ($page=1;$page<=$number_of_pages;$page++) {
echo "<li><a href='search_results.php?page=".$page."'>".$page."</a></li>";
}
}
?>
html
<form action="search_results.php" method="POST">
<input type="text" name="search"placeholder="Search">
<button type="submit" name="submit-search">go</button>
</form>

Answer 1

The logic is wrong.
// this code is only executed on the initial search.
if (isset($_POST['submit-search'])) {
When the user go's to the next page:
echo "<li><a href='search_results.php?page=".$page."'>".$page."</a></li>";
Only a page number is given and the search parameter is lost as nothing is posted, so the first if statement will not run again.
You could do something like:
echo "<li><a href='search_results.php?page=".$page."&search=$search'>".$page."</a></li>";
And:
if(isset($_POST['submit-search']) || isset($_GET['search'])){
$search = ...;
}