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In this tutorial, you will learn how to build unique visitor counter with Codeigniter.with simple and more effective ways. This way have also another feature. It will save more performance and more database query usage by using cookie 

First step I will suppose you will already have articles table like this

CREATE TABLE IF NOT EXISTS `articles` (
  `article_id` int(11) NOT NULL AUTO_INCREMENT,
  `article_cat_id` int(11) NOT NULL,
  `article_name` varchar(255) NOT NULL,
  `article_slug` varchar(255) NOT NULL,
  `article_body` text NOT NULL,
  `img_link` varchar(255) DEFAULT NULL,
  `article_state` tinyint(1) NOT NULL DEFAULT '0',
  `article_views` int(11) NOT NULL,
  `article_created` int(11) NOT NULL,
  PRIMARY KEY (`article_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=6 ;

If you don’t have article_views column then you should add this column. You will use this column to increase counter with every visit to your article page

The second step I will suppose you will already have function to show articles like this

class article extends CI_Controller
{
Function Show_article($slug){
// here you put your query to select the article 
//by slug or whatever by id
//then call the counter function  and pass the slug or the 
//id for the counter function
$this->add_count($slug);
}
 

// This is the counter function.. 
function add_count($slug)
{
// load cookie helper
    $this->load->helper('cookie');
// this line will return the cookie which has slug name
  $check_visitor = $this->input->cookie(urldecode($slug), FALSE);
// this line will return the visitor ip address
    $ip = $this->input->ip_address();
// if the visitor visit this article for first time then //
 //set new cookie and update article_views column  ..
//you might be notice we used slug for cookie name and ip 
//address for value to distinguish between articles  views
    if ($check_visitor == false) {
        $cookie = array(
            "name"   => urldecode($slug),
            "value"  => "$ip",
            "expire" =>  time() + 7200,
            "secure" => false
        );
        $this->input->set_cookie($cookie);
        $this->news->update_counter(urldecode($slug));
    }
}
}

The last step to update database counter in the article model

class article_model extends CI_Model {

function update_counter($slug) {
// return current article views 
    $this->db->where('article_slug', urldecode($slug));
    $this->db->select('article_views');
    $count = $this->db->get('articles')->row();
// then increase by one 
    $this->db->where('article_slug', urldecode($slug));
    $this->db->set('article_views', ($count->article_views + 1));
    $this->db->update('articles');
}
}

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