Reply To: Simple PHP Pagination

[__]

The first function, to determine the offset for your query, would look something like this:

function pagination_getOffset( $page,$itemsPerPage ){
    // make sure both args are integers
    if(
        ! ctype_digit( (string)$page )
        || ! ctype_digit( (string)$itemsPerPage )
    ){
        return 0;
    }
    return ($page - 1) * $itemsPerPage;
}

The second would create your pagination links. Since you only want prev/next links, it’s pretty simple:

function pagination_html( $page,$totalPages ){
    // make sure both args are integers; current page cannot be greater than total pages
    if(
        ! ctype_digit( (string)$page )
        || ! ctype_digit( (string)$totalPages )
        || $page > $totalPages
    ){
        return false;
    }
    // this var will hold the HTML markup
    $html = '';
    // no "prev" link if on first page
    if( $page > 1 ){
        $html .= '<a href="?page='.($page - 1).'" rel="previous">Previous</a>';
    }
    // no "next" link on last page
    if( $page < $totalPages ){
        $html .= '<a href="?page='.($page + 1).'" rel="next">?Next</a>';
    }
    // done
    return $html;
}

Usage would be like so:

<?php
// determine requested page, default to page 1
$page = isset( $_GET['page'] )? 
    $_GET['page']: 
    1;

// decide # of items per page
$limit = 30;

// determine offset for SQL statement
$offset = pagination_getOffset( $page,$limit );

// write your sql
$sql = "SELECT SQL_CALC_FOUND_ROWS ID, TITLE, COVER_URL FROM movies"
    ." ORDER BY id DESC"
    ." LIMIT $offset, $limit";
// do your query, etc..
//  . . .

// use @BenWalker's suggestion to get total # of pages
$sql = "SELECT FOUND_ROWS()";
// do the query, assign result to $totalPages
//  . . .

// get pagination links
$paginationHTML = pagination_html( $page,$totalPages );

// print where desired on page
echo $paginationHTML;