SAVE COOKIES

dbconnect
lesson44.php
connect to database
<?php
$host = 'localhost';
$user = 'root';
$pass = '';
$dbname = 'lesson44';
if($mycon = @mysqli_connect($host, $user, $pass)){
if(@mysqli_select_db($mycon, $dbname)){
//echo 'connected to the DB';
} else {
//echo 'DB connection failed';
} }
else {
//echo 'server connection failed';
}
?>
core.php
<?php
ob_start();	to start the header we wiil use this
//to use header we have to start this
session_start();	to save cookies we have to start sessions,logged in till log out,using this only
$current_file = $_SERVER['SCRIPT_NAME'];	using this we can get the url of the present page
//IT WILL Bcarry basic data - it will give the url withoud domainname /login.php
function loggedin(){	implement logged in function, we can call this funtuin by placing this page and call this function
if (isset($_SESSION['user_id']) && !empty($_SESSION['user_id'])){ return true;}	if we got the value in user id , any rows are matched, matched means not empty , so it returns
else{return false;}
}
?>
login.php
<?php
if(isset($_POST['username'])&&isset($_POST['password'] )  ){	user name and password is submitted
$username = $_POST ['username'];	load that entered username and password to some variables
$password = $_POST['password'];
$pass_hash = md5($password);	convert that entered pasword to md5
if(!empty($username) &&!empty($password)){	username values and password values are not empty
$query = "SELECT `id` FROM `users` WHERE `username` = '$username' AND `password` = '$pass_hash' ";	//entered username and password , match using this query, if match, it writes how many number of rows match,if not match  it will write 0
if ($query_run = mysqli_query($mycon, $query ) ) {	//mycon is not there in this  page and we not used this in this database, so we have to understand we are not using this page directly, we r creting template for another page, at that we used reuqire
$num_rows = mysqli_num_rows($query_run);	get the how many matched rows, u can see how many rows are matched using echo
if ($num_rows == 0){echo 'invalid username and password';}	if rows are not matched , enter valid password
	// 0 means no row is matched, so entered thing is fault
else if ($num_rows == 1){$row = mysqli_fetch_row($query_run); echo $id = $row[0];}	if rows are mached , ur id is matched and it shows valid things
	// it will print whats the id matched
	//if enetered username and password is matched with database, it generates some rows  or convert ted arrays and prints that array using array access
	//after matched we have to start session
$_SESSION['user_id'] = $id;	write the array data to sesssion
//session variable is set
// close browser, loggged out means session variable destroyed
header('Location: lesson47.php');	print the logged in using this in header
}	in this page we are using , we not declared some variable in this page, eventhough we willl use, because, we run another page , we access that vairable via that page
else {echo 'please enter username and password!';}
?>
<form action="<?php echo $current_file ?>" method="post">
username: <input type="text" name="username"> <br><br>
password: <input type="password" name="password"> <br> <br>
<input type="submit" value="log in">
</form>

@mysqli_connect

@mysqli_select_db

$_SERVER['SCRIPT_NAME']

isset

($_SESSION['user_id']

isset

$_POST

IF IF IF ELSEIF ELSE

!EMPTY

SELECT FROM WHERE

mysqli_query

mysqli_num_rows

$_SESSION['user_id']

header