<?php
$connection = mysqli_connect("localhost", "data", "aaa");

$db = mysqli_select_db("dados", $connection);
session_start();// Starting Session

$user_check=$_SESSION['login_user'];

$ses_sql=mysqli_query("select username from login where username='$user_check'", $connection);
$row = mysqli_fetch_assoc($ses_sql);
$login_session =$row['username'];
if(!isset($login_session)){
mysqli_close($connection); // Closing Connection
header('Location: index.php'); // Redirecting To Home Page
}
?>


    <?php
session_start(); // Starting Session
$error=''; // Variable To Store Error Message
if (isset($_POST['submit'])) {
if (empty($_POST['username']) || empty($_POST['password'])) {
$error = "Username ou Password são inválidos";
}
else
{
// Define $username and $password
$username=$_POST['username'];
$password=$_POST['password'];
// Establishing Connection with Server by passing server_name, user_id and password as a parameter
$connection = mysqli_connect("localhost", "data", "aaa");
// Check connection
//if ($connection->connect_error) {
  //  die("Connection failed: " . $connection->connect_error);
//}
//echo "Connected successfully";
// To protect MySQL injection for Security purpose
$username = stripslashes($username);
$password = stripslashes($password);
$username = mysqli_real_escape_string($username);
$password = mysqli_real_escape_string($password);
// Selecting Database
$db = mysqli_select_db("dados", $connection);
// SQL query to fetch information of registerd users and finds user match.
$query = mysqli_query("select * from login where password='$password' AND username='$username'", $connection);
$rows = mysqli_num_rows($query);
if ($rows == 1) {
$_SESSION['login_user']=$username; // Initializing Session
header("Location: menu.php"); // Redirecting To Other Page
} else {
$error = "Username ou Password são inválidosS";
}
mysqli_close($connection); // Closing Connection
}
}
?>