php code for simple login applicationLearning Curve- Perfect Tutorial for the beginers | Learning Curve- Perfect Tutorial for the beginers

Simple login application using php:Login application using php and mysql

Use the following steps create database called ‘testlogin’ and execute the following query

CREATE TABLE IF NOT EXISTS `tbl_login` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `username` varchar(100) NOT NULL,
  `password` varchar(100) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

--
-- Dumping data for table `tbl_login`
--

INSERT INTO `tbl_login` (`id`, `username`, `password`) VALUES
(1, 'admin', 'admin');

CREATE TABLE IF NOT EXISTS `tbl_login` (

`id` int(10) NOT NULL AUTO_INCREMENT,

`username` varchar(100) NOT NULL,

`password` varchar(100) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

-- Dumping data for table `tbl_login`

INSERT INTO `tbl_login` (`id`, `username`, `password`) VALUES

(1, 'admin', 'admin');

please save the below files into a folder under htdocs. index.php

<html>
<head>
<title>Simple Login using php-session</title>
<script type="text/javascript">
function validate()

{

if(document.form1.username.value=='')
{
alert("please enter the user name");
document.form1.username.focus();
return false;

}
if(document.form1.password.value=='')
{
alert("please enter the password");
document.form1.password.focus();
return false;
}
return true;

}

</script>
</head>
<body>
<form method="post" action="postdata.php" id="form1" name="form1" autocomplete="off">
 
<table border="1" cellspacing="0" cellpadding="0" align="center" width="350">
<tr>
<td width="1px">User Name:</td>
<td width="1px"><input type="text" name="username" value=""></td>
</tr>
<tr>
<td width="1px">Password</td>
<td width="1px"><input type="password" name="password" value=""></td>
</tr>
<tr>
<td width="1px"></td>
<td width="1px"><input type="Submit" name="Submit" value="Login" onclick="return validate();"></td>
</tr>
<tr>
<td width="1px"></td>
<td width="1px"><div style="text-color=red;"><?php echo @$_GET['msg'];?></div></td>
</tr>
</table> 
</form>
</body></html>

<html>

<head>

<title>Simple Login using php-session</title>

function validate()

{

if(document.form1.username.value=='')

{

alert("please enter the user name");

document.form1.username.focus();

return false;

}

if(document.form1.password.value=='')

{

alert("please enter the password");

document.form1.password.focus();

return false;

}

return true;

}

</script>

</head>

<body>

<tr>

</tr>

<tr>

<td width="1px">Password</td>

</tr>

<tr>

</tr>

<tr>

</tr>

</table>

</form>

</body></html>

database.php

<?php
$connection_string = mysql_connect('localhost', 'root', '');
if (!$connection_string) {
    die('Could not connect: ' . mysql_error());
}
 mysql_select_db('testlogin', $connection_string) or die('Could not select database.');

?>

<?php

$connection_string = mysql_connect('localhost', 'root', '');

if (!$connection_string) {

die('Could not connect: ' . mysql_error());

}

mysql_select_db('testlogin', $connection_string) or die('Could not select database.');

postdata.php

<?php
session_start();
include"database.php";

$user=@$_POST['username'];
$password=@$_POST['password'];
$query="select * from tbl_login where username='$user' and password='$password'";
$sql_result=mysql_query($query,$connection_string);
$num_rows=mysql_num_rows($sql_result);
if($num_rows>0)
{
@$_SESSION['userdetails']=$user;
header("Location:admin.php");
}
else
{
$errormessage="Login failed";
header("Location:index.php?msg=$errormessage");
}
?>

<?php

session_start();

include"database.php";

$user=@$_POST['username'];

$password=@$_POST['password'];

$query="select * from tbl_login where username='$user' and password='$password'";

$sql_result=mysql_query($query,$connection_string);

$num_rows=mysql_num_rows($sql_result);

if($num_rows>0)

{

@$_SESSION['userdetails']=$user;

header("Location:admin.php");

}

else

{

$errormessage="Login failed";

header("Location:index.php?msg=$errormessage");

}

admin.php

<?php
session_start();
if(@$_SESSION['userdetails']=="")
{
header("Location:index.php");
}
?>
<html>
<head>
<title>Simple Login using php and mysql</title>

</head>
<body>

<table border="1" cellspacing="0" cellpadding="0" align="center" width="350">
<tr>
<td width="1px">Welocome : <?php echo $_SESSION['userdetails'];?></td>
<td width="1px"></td>
</tr>
<tr>
<td width="1px"><a href="logout.php">Logout</a></td>
<td width="1px"></td>
</tr>
</table> 
</body></html>

<?php

session_start();

if(@$_SESSION['userdetails']=="")

{

header("Location:index.php");

}

<html>

<head>

<title>Simple Login using php and mysql</title>

</head>

<body>

<tr>

<td width="1px">Welocome : <?php echo $_SESSION['userdetails'];?></td>

</tr>

<tr>

<td width="1px"><a href="logout.php">Logout</a></td>

</tr>

</table>

</body></html>

logout.php

<?php
session_start();
session_destroy();
session_unset();
unset($_SESSION['userdetails']);
header("Location:index.php");
?>

<?php

session_start();

session_destroy();

session_unset();

unset($_SESSION['userdetails']);

header("Location:index.php");