Simple pagination class in PHP

File: paginator.php

 

<?php
require_once 'DB.php';

class Paginator
{
    private $queryStr;
    private $pageSize;
    private $currentPage=1;
    private $conn;
    private $totalRecords;
    private $totalPages;
   
    public function __construct($queryStr,$pageSize,$totalRecords)
    {
        $this->conn=DB::db_connect();
        $this->queryStr=$queryStr;
        if(isset($_REQUEST['showpage']))
        $this->currentPage=$_REQUEST['showpage'];
        $this->pageSize=$pageSize;
        $this->totalRecords=$totalRecords;
        $this->totalPages=ceil(($this->totalRecords)/($this->pageSize));
    }
   
    public function getPage()
    {
        $offset=($this->currentPage-1)*($this->pageSize);
        $queryStr="$this->queryStr limit $offset,$this->pageSize";   
        $result=$this->conn->query($queryStr);
        return $result;               
    }
   
    public function showNavigationLinks()
    {
        echo "<div id='nav'>";
       
        if($this->currentPage>1)
        {
            echo "<a href=index.php?showpage=".($this->currentPage-1).">Prev</a>";
        }
       
        echo "&nbsp";
       
        for($i=1;$i<=$this->totalPages;$i++)
        {
            echo "<a href=index.php?showpage=".$i.">".$i."</a>&nbsp";
        }
       
        echo "&nbsp";
       
        if(($this->totalRecords)>($this->currentPage)*($this->pageSize))
        {
            echo "<a href=index.php?showpage=".($this->currentPage+1).">Next</a>";
        }
       
        echo "</div>";
       
    }
   
}

?>

File: DB.php

<?php

class DB
{
    public static function db_connect()
    {
       $result = new mysqli('localhost', 'root', '', 'test');
       if (!$result)
          return false;
       return $result;
    }   

}

?>

File: index.php

<?php

require_once 'paginator.php';
require_once 'DB.php';

//I have a table 'countries' having two fields id, name

$mainquery='Select * from countries';
$countquery='Select count(id) as rec_count from countries';
$conn=DB::db_connect();
$result=$conn->query($countquery);
$row=$result->fetch_object();
$totalRecords=$row->rec_count;



$pg=new Paginator($mainquery,6,$totalRecords);
$pageData=$pg->getPage();

while($row=$pageData->fetch_object())
{
    echo '<br />'.$row->id.'-'.$row->name;   
}
echo '<br />';
$pg->showNavigationLinks();

?>