Modern Programming Languages

 

  Login page:

    <? 
        // start session
            session_start(); 
       // convert username and password from _POST or _SESSION
            if($_POST)

              {
                  $_SESSION['username']=$_POST["username"];
                  $_SESSION['password']=$_POST["password"];  
               }
      

     // Sql query for a username&password 
         $result=mysql_query("select * from users where username='" . $_SESSION['username'] . "' and password='" . $_SESSION['password'] . "'"); 
     

     //     retrieve number of rows resulted
        $num=mysql_num_rows($result);  
     //    print login form and exit if failed.
         if($num < 1)

           {
               echo "You are not authenticated.  Please login.<br><br> 
                 <form method=POST action=index.php>
                          username: <input type=text name=\"username\"> 
                          password: <input type=password name=\"password\">
                     <input type=submit> 
                </form>"; 
             exit;
          }
    ?>

  Slq-Query

    CREATE TABLE USERS(  User_id int(8)unsigned NOT NULL auto_increment, username varchar(20) NOT NULL default '', password varchar(20) NOT NULL default '',

       PRIMARY KEY (user_id)  )TYPE=MyISAM

   <?
    // Login & Session example by sde connect.php
    // replace with your db info
          $hostname="localhost";
          $mysql_login="myusername";
          $mysql_password="mypass";
          $database="test";

        if (!($db = mysql_connect($hostname, $mysql_login , $mysql_password)))
          {
               die("Can't connect to mysql.");    
             }

          else

             {
                if (!(mysql_select_db("$database",$db))) 

                   {
                      die("Can't connect to db.");
                     }
              }
       ?>