I am building a study planner that features just a single welcome area, after logging in. I am currently trying to obtain the user ID of the currently logged in user for use in an SQL update query in this welcome area, as well as the user’s first name for use in the welcome message.
I have tried putting $_SESSION['user_id'] = userid; and $_SESSION['user_firstname'] = firstname; after $_SESSION['login_user'] = $username; ($_SESSION['login_user'] = $username; works fine by the way) but upon logging into the page, I get these errors: Notice: Use of undefined constant userid - assumed 'userid' in C:\wamp64\www\justread\session.php on line 11 and Notice: Use of undefined constant firstname - assumed 'firstname' in C:\wamp64\www\justread\session.php on line 12.
Now, I know the errors want me to do some sort of initialisation for ‘userid’ and ‘firstname’ first before using them to set up a session variable but I am not sure how to go about it, so I am wondering if someone could help me, please.
Thanking you in advance.
I can post more codes if required but the codes I believe are concerned are:
login.php:
<?php
// Start session
session_start();
// Variable to store error message
$error ="";
// If the login form (Note that the 'submit' refers to the 'name' attribute of the login form) has been submitted...
if (isset($_POST['submit'])) {
// If username or password is not provided...
if (empty($_POST['username']) || empty($_POST['password'])) {
// ...tell user that login details are invalid.
$error = "Please fill in both your username and your password";
// Else...
} else {
// ...put the provided username and password in variables $username and $password, respectively
$username = $_POST['username'];
$password = $_POST['password'];
// Establish connection to the server
$mysqli = mysqli_connect("localhost", "root", "");
// set up measures to counter potential MySQL injections
$username = stripslashes($username);
$password = stripslashes($password);
$username = mysqli_real_escape_string($mysqli, $username);
$password = mysqli_real_escape_string($mysqli, $password);
// Select Database
$db = mysqli_select_db($mysqli, "p00702");
// SQL query to fetch information of registerd users and find user match.
$query = mysqli_query($mysqli, "SELECT * from logins WHERE password='$password' AND username='$username'");
// Return the number of rows of the query result and put it in $rows variable
$rows = mysqli_num_rows($query);
// If rows are equal to one...
if ($rows == 1) {
unset($_SESSION['error']);
// Initialize session with the username of the user...
$_SESSION['login_user'] = $username;
// Set the user ID of the user
$_SESSION['user_id'] = userid;
// Set the user first name of the user
$_SESSION['user_firstname'] = firstname;
// ...and redirect to the homepage.
header("Location: welcome.php");
// Make sure that codes below do not execut upon redirection.
exit;
// Else,
} else {
// and tell user that the login credentials are invalid.
$error = "Your username or password is invalid";
$_SESSION['error'] = $error;
// redirect user to the home page (index.php)
header("Location: index.php");
}
// ...and close connection
mysqli_close($mysqli);
}
}
session.php
<?php
// Establish connection to the server
$mysqli = mysqli_connect("localhost", "root", "");
// Selecting Database
$db = mysqli_select_db($mysqli, "p00702");
// Starting session
session_start();
// Storing Session
$user_check = $_SESSION['login_user'];
$_SESSION['user_id'] = userid;
$_SESSION['user_firstname'] = firstname;
// Test to see the content of the global session variable
print_r($_SESSION);
// SQL Query To Fetch Complete Information Of User
$ses_sql = mysqli_query($mysqli, "SELECT username FROM logins WHERE username='$user_check'");
$row = mysqli_fetch_assoc($ses_sql);
$login_session = $row['username'];
if (!isset($login_session)) {
// Closing Connection
mysqli_close($mysqli);
// Redirecting To Home Page
header('Location: index.php');
// Make sure that codes below do not execut upon redirection.
exit;
}
