PHP - Contador de visitas por entrada (id) con php y mysql

<?php

//MySQL database variables

//You need to change these variables to be right for your MySQL install

$host = "localhost";

$user = "root";

$pass = "";

$dbname = "click_count";

//DO NOT CHANGE THE FOLLOWING CODE!

//start a PHP session

//this prevents spamming the click count by refreshing the page

session_start();

//create current page constant

$curPage = mysql_real_escape_string(htmlspecialchars($_SERVER['PHP_SELF']));

//set number of clicks variable to 0

$clicks = 0;

//do not recount if page currently loaded

if($_SESSION['page'] != $curPage) {

   //set current page as session variable

   $_SESSION['page'] = $curPage;

   //try to connect to MySQL server

   if(!$link = mysql_connect($host, $user, $pass)) {

      echo "Could not connect to MySQL server. Check your login information; the MySQL server may also be offline or temporarily overloaded.";

   }

   //try to select database

   elseif(!mysql_select_db($dbname)) {

      echo "Cannot select database.";

   }

   else {

      //get current click count for page from database;

      //output error message on failure

      if(!$rs = mysql_query("SELECT * FROM click_count WHERE page_url = '$curPage'")) {

         echo "Could not parse click counting query.";

      }

      //if no record for this page found,

      elseif(mysql_num_rows($rs) == 0) {

         //try to create new record and set count for new page to 1;

         //output error message if problem encountered

         if(!$rs = mysql_query("INSERT INTO click_count (page_url, page_count) VALUES ('$curPage', 1)")) {

            echo "Could not create new click counter for this page.";

         }

         else {

            $clicks = 1;

         }

      }

      else {

         //get number of clicks for page and add 1

         $row = mysql_fetch_array($rs);

         $clicks = $row['page_count'] + 1;

         //update click count in database;

         //report error if not updated

         if(!$rs = mysql_query("UPDATE click_count SET page_count = $clicks WHERE page_url = '$curPage'")) {

            echo "Could not save new click count for this page.";

         }

      }

   }

}

?>