1.PHP for Database Connection

registration.php

<html>
<head>
	<title>Registration</title>
</head>
<body>
		<h2>Register</h2>
	<form method="post" action="regProcess.php">
			<label>Username</label>
			<input required ="required"type="text" name="username">
			<label>Email</label>
			<input type="email" name="email">
			<label>Password</label>
			<input type="password" name="password">
			<button type="submit" class="btn" name="register_btn">Register</button>
	</form>
</body>
</html>

regprocess.php

<?php
	require('dbconn.php');
    if (isset($_POST['register_btn'])){
		$username    = $_POST['username'];
		$email       = $_POST['email'];
		$password  = $_POST['password'];
		$query = "INSERT into `user` (Username, Email, Password) VALUES ('$username', '$email', '$password')";
        $result = mysqli_query($con,$query);
        if($result){
            echo "You are registered successfully.";
        }
    }else{
		echo "Faild.";
	}
?>


login.php


<html>
<head>
	<title>Login</title>
</head>
<body>
		<h2>Register</h2>
	<form method="post" action="loginProcess.php">
			<label>Username</label>
			<input type="text" name="username">
			<label>Password</label>
			<input type="password" name="password">
			<button type="submit" class="btn" name="login_btn">Login</button>
	</form>
</body>
</html>


loginprocess.php


<?php
		require('dbconn.php');
        if (isset($_POST['login_btn'])){
		$username    = $_POST['username'];
		$password = $_POST['password'];

		$query = "SELECT * FROM user WHERE username='$username' AND password='$password'";
		$results = mysqli_query($con, $query);

	    if (mysqli_num_rows($results) == 1) {
		echo "$username Login Successfully";
		}
		else
		{
			echo "Login faild";
		}
	}
?>


dbconn.php


<?php
$con = mysqli_connect("localhost","root","","user");
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }
else
  {
	echo "Database Connection Successfull";
  }
?>