PHP Login script tutorial

Learn to create a simple login system with PHP + MySql script, this tutorial easy to follow, teach you step by step.

• Overview
  

In this tutorial create 3 files

1. main_login.php
2. checklogin.php
3. login_success.php

Step

1. Create table "members" in database "test".
2. Create file main_login.php.
3. Create file checklogin.php.
4. Create file login_success.php.
5. Create file logout.php 

• Create table "members" 

                                                    CREATE TABLE `members` (
                                                    `id` int(4) NOT NULL auto_increment,
                                                    `username` varchar(65) NOT NULL default '',
                                                    `password` varchar(65) NOT NULL default '',
                                                    PRIMARY KEY (`id`)
                                                    ) TYPE=MyISAM AUTO_INCREMENT=2 ;

                                                    --
                                                    -- Dumping data for table `members`
                                                    --

                                                    INSERT INTO `members` VALUES (1, 'john', '1234');

This is how table looks in database:

• Create file main_login.php

Code:                                                  

                                                   <table width="300" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
                                                   <tr>
                                                   <form name="form1" method="post" action="checklogin.php">
                                                   <td>
                                                   <table width="100%" border="0" cellpadding="3" cellspacing="1" bgcolor="#FFFFFF">
                                                   <tr>
                                                   <td colspan="3"><strong>Member Login </strong></td>
                                                   </tr>
                                                   <tr>
                                                   <td width="78">Username</td>
                                                   <td width="6">:</td>
                                                   <td width="294"><input name="myusername" type="text" id="myusername"></td>
                                                   </tr>
                                                   <tr>
                                                   <td>Password</td>
                                                   <td>:</td>
                                                   <td><input name="mypassword" type="text" id="mypassword"></td>
                                                   </tr>
                                                   <tr>
                                                   <td> </td>
                                                   <td> </td>
                                                   <td><input type="submit" name="Submit" value="Login"></td>
                                                   </tr>
                                                   </table>
                                                   </td>
                                                   </form>
                                                   </tr>
                                                   </table>

This is how it looks in browser

• Create file checklogin.php 

Code:                                       

                                                   <?php

                                                            $host="localhost";// Host name
                                                            $username=""; // Mysql username
                                                            $password=""; // Mysql password
                                                            $db_name="test"; // Database name
                                                            $tbl_name="members"; // Table name

                                                            // Connect to server and select databse.

                                                            mysql_connect("$host", "$username", "$password")or die("cannot connect");
                                                            mysql_select_db("$db_name")or die("cannot select DB");

                                                            // username and password sent from form

                                                            $myusername=$_POST['myusername'];
                                                            $mypassword=$_POST['mypassword'];

                                                             // To protect MySQL injection

                                                            $myusername = stripslashes($myusername);
                                                            $mypassword = stripslashes($mypassword);
                                                            $myusername = mysql_real_escape_string($myusername);
                                                            $mypassword = mysql_real_escape_string($mypassword);

                                                            $sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
                                                            $result=mysql_query($sql);

                                                            // Mysql_num_row is counting table row

                                                            $count=mysql_num_rows($result);

                                                            // If result matched $myusername and $mypassword, table row must be 1 row

                                                            if($count==1){

                                                            // Register $myusername, $mypassword and redirect to file "login_success.php"

                                                            session_register("myusername");
                                                            session_register("mypassword");
                                                            header("location:login_success.php");
                                                            } else {
                                                            echo "Wrong Username or Password";
                                                            }

                                                    ?>

• Note:    For PHP5 User - checklogin.php 
  

                                                             ob_start();
                                                             $host="localhost"; // Host name
                                                             $username=""; // Mysql username
                                                             $password=""; // Mysql password
                                                             $db_name="test"; // Database name
                                                             $tbl_name="members"; // Table name

                                                             // Connect to server and select databse.

                                                             mysql_connect("$host", "$username", "$password")or die("cannot connect");
                                                             mysql_select_db("$db_name")or die("cannot select DB");

                                                             // Define $myusername and $mypassword

                                                             $myusername=$_POST['myusername'];
                                                             $mypassword=$_POST['mypassword'];

                                                             // To protect MySQL injection

                                                             $myusername = stripslashes($myusername);
                                                             $mypassword = stripslashes($mypassword);
                                                             $myusername = mysql_real_escape_string($myusername);
                                                             $mypassword = mysql_real_escape_string($mypassword);

                                                             $sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
                                                             $result=mysql_query($sql);

                                                             // Mysql_num_row is counting table row

                                                             $count=mysql_num_rows($result);

                                                             // If result matched $myusername and $mypassword, table row must be 1 row

                                                             if($count==1){

                                                             // Register $myusername, $mypassword and redirect to file "login_success.php"

                                                             session_register("myusername");
                                                             session_register("mypassword");
                                                             header("location:login_success.php");
                                                             } else {
                                                             echo "Wrong Username or Password";
                                                             }

                                                             ob_end_flush();

                                                     ?>

• Create file login_success.php  

 Code:

                                                       // Check if session is not registered , redirect back to main page.
                                                       // Put this code in first line of web page.

                                                       <?php

                                                                session_start();
                                                                if(!session_is_registered(myusername)){
                                                                header("location:main_login.php");
                                                                }

                                                       ?>

                                                       <html>
                                                       <body>
                                                        Login Successful
                                                       </body>
                                                       </html>

• Logout.php 

If you want to logout, create this file

Code:

                                                        // Put this code in first line of web page.

                                                        <?php

                                                                 session_start();
                                                                 session_destroy();

                                                        ?>