MyCodeStock

Demo :

Code Begins :

check.php :

<?php
$link = mysql_connect('localhost', 'root', '');
if (!$link) {
    die('Not connected : ' . mysql_error());
}

$db_selected = mysql_select_db('test', $link);
if (!$db_selected) {
    die ('Can\'t use test table : ' . mysql_error());
}

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

$query="select * from user where username='".$username."'";
$result=mysql_query($query);
$records=mysql_fetch_array($result);

if($records)
{
 if($password==$records['password'])
 {
  session_start();
  $_SESSION['username']=$records['username'];
  $_SESSION['userid']=$records['id'];
  header('Location: home.php');
 }
 else
 {
  $msg="Password Incorrect";
  header('Location: index.php?msg='.$msg);
 }
}
else
{
 $msg="Username Incorrect";
 header('Location: index.php?msg='.$msg);
}
?>

index.php :

<!DOCTYPE HTML>
<html>
<head>
<title>Login System</title>
</head>
<body>

<h1>Login Form</h1>
<?php

if(isset($_GET['msg']))
{
 $msg=$_GET['msg'];
 echo '<p><font color="red">';
 echo $msg;
 echo '</font></p>';
}
?>
<form action="check.php" method=POST>
  <label for="username">Username</label>
  <input type="text" name="username" id="username" placeholder="username"><br>
  <label for="password">Password</label>
  <input type="password" name="password" id="password"  placeholder="password"><br><br>
  <input type="submit" value="Submit">
</form>
</body>
</html>

home.php :

<?php
session_start();
$username=$_SESSION['username'];
$userid=$_SESSION['userid'];

echo "You Are Logged IN -<b>".$username."</b> and your ID is -<b>".$userid."</b>";
?>

Steps To Execute Query In Wordpress  :

In the query writing method which I'll be showing here, it is very easy to add new column data and also this query looks good and is in easy readable form.

CODE BEGINS :

Here's the code :

replace() function syntax :

replace() function usage :