Make a Login System for Your Website: PHP and MySQL

1. Run this SQL command in your MySQL database (you must have one):
   CREATE TABLE `users` (
   `id` int(3) NOT NULL auto_increment,
   `login` varchar(8) default NULL,
   `password` varchar(8) default NULL,
   PRIMARY KEY (`id`)
   ) TYPE=MyISAM AUTO_INCREMENT=3 ;
   This will create the table that will record the usernames and passwords.
2. Then, create the LOGIN.PHP file. This page will contain the form that will submit the user´s data.
   
   
   session_name("MyLogin");session_start();session_destroy();
   if($_GET['login'] == "failed") {print $_GET['cause'];
   }?>
   
   Login:
   
   Password:
   
   
3. Now, create the LOG.PHP. This is the file that performs the action of the form.
   
   
   session_name("MyLogin");session_start();
   if($_GET['action'] == "login") {$conn = mysql_connect("localhost","user","password"); // your MySQL connection data$db = mysql_select_db("DATABASENAME"); //put your database name in here
   $name = $_POST['user'];$q_user = mysql_query("SELECT * FROM USERS WHERE login='$name'");
   1. if(mysql_num_rows($q_user) == 1) {
      $query = mysql_query("SELECT * FROM USERS WHERE login='$name'");$data = mysql_fetch_array($query);if($_POST['pwd'] == $data['password']) { session_register("name");header("Location: yourpage.php"); // success page. put the URL you want exit;} else {header("Location: login.php?login=failed&cause=".urlencode('Wrong Password'));exit;}} else {header("Location: login.php?login=failed&cause=".urlencode('Invalid User'));exit;}
      }
      // if the session is not registeredif(session_is_registered("name") == false) {header("Location: login.php");
      }?>
   2. If you paid enough attention, you noticed that the login will lead the user to YOURPAGE.PHP. Add these lines of code to any webpage that you want to secure (including yourpage.php):
      
      
      require("log.php");?>
      Printing the user name in the screen is very easy. Just add this code:
      print $_SESSION["name"]; ?>