How to create page numbers (for navigation) on a web page - php

Question

I am writing PHP script to display data from the database (Mysql) on my webpage. I don't want all the information to display on a single page to avoid scrolling. However, I want to display only a few and then use page numbers to navigate to the rest. I managed to create the page numbers and yet still all the information is showing on a single page. Below is my code:
<?php
include('./includes/DB_Config.php');
$status = 1;
// Set number of Post per page for navigation
$post_per_page = 2;
if (isset($_GET['page']))
{
$startP = ($_GET['page'] - 1) * $post_per_page;
}
else
{
$startP = 0;
}
$post = mysqli_query ($mySQL_Conn, "SELECT * FROM BlogPost WHERE status = '$status'");
// Fetch Data or number of rows
$dataRw = mysqli_num_rows($post);
$pages = $dataRw / $post_per_page;
if ($dataRw == 0)
{
$_SESSION['NoPost'] = "No Post Found!";
}
else
{
unset($_SESSION['NoPost']);
//$pages = ceil($dataRw / $rows_per_page);
//$pages = array_slice($dataRw, $startP, $post_per_page);
while ($data = mysqli_fetch_array($post)) //Fetch data in array
{
//Assign data to variabes
$name = $data['blogger_Name'];
$postDate = $data['dateTime'];
$blogpost = $data['blog_message'];
$date = strtotime($postDate);
?>
<p> <span><?php echo $_SESSION['NoPost'] ; ?> </span></p>
<p> <span>By:</span><?php echo $name; ?> </p>
<p> <span>Posted On: </span> <?php echo date("j F Y", $date); ?> </p>
<p> <span>Post: </span><?php echo $blogpost; ?> </p>
<?php
}
}
?>
<hr>
<?php
for ($currentpage = 0; $currentpage < $pages; $currentpage++ )
{
?>
<span> <?php echo $currentpage + 1; ?> </span>
<?php
}
?>

Answer 1

What you are trying to accomplish is a very common pattern, and it's called pagination.
You can use LIMIT and OFFSET in your mysql queries to get only a certain subset of the data, and you can use this for basic pagination.
For example, if you want to display 50 results per page, and the user is on the third page, you set LIMIT to 50 and OFFSET to 2*50 (100), keep in mind the first page is an offset of 0 so we subtract the page by one.
You can use the following sql query to get a subset of data for a specific page.
"SELECT * FROM Users LIMIT $num_results OFFSET ".(($page_num-1)*$num_results);
You can get the total number of possible pages by getting the total row count from the Users table and dividing it by $num_results. A good idea might be to have your output script take a GET url query parameter that will be used as the page number.