我有一个有效的登录系统，可以检查每个页面是否登录用户。我还添加了一个列“usertype”，其中0表示学生，1表示教授，2表示头部，3表示工作人员。当我试图检查用户组是1还是2等...它不起作用时，即使我在数据库中的帐户设置为1，也不会在页面中显示任何内容。如果有人帮我查找什么是错的，这将是伟大的！提前谢谢。
这是我的覆盖页面：
<?php
include_once 'includes/db_connect.php';
include_once 'includes/functions.php';
sec_session_start();
$servername = "localhost";
$username = "";
$password = "";
$dbname = "";
$user = $_SESSION['username']
?>
<!DOCTYPE html>
<html>
<?php if (login_check($mysqli) == true) : ?>
<p>Welcome <?php echo htmlentities($_SESSION['username']); ?>!</p>
<?php if ($_SESSION['usertype'] == 1) { ?>
<form method="post" action="dboverride.php" name="OverrideForm" id="OverrideForm" autocomplete="off">
<fieldset>
<legend><b>Personal Details</b></legend>
<div>
<label for="name" accesskey="N">First Name</label>
<?php
$mysqli = new Mysqli($servername, $username, $password, $dbname) or die(mysql_error());
$name = $mysqli->query("SELECT name FROM student WHERE username = '$user'")->fetch_object()->name;
print_r($name);
?>
</div>
<br>
<div>
<label for="mname" accesskey="M">Mid. Name</label>
<?php
$mysqli = new Mysqli($servername, $username, $password, $dbname) or die(mysql_error());
$mname = $mysqli->query("SELECT mname FROM student WHERE username = '$user'")->fetch_object()->mname;
print_r($mname);
?>
</div>
<br>
<div>
<label for="fname" accesskey="F">Last Name</label>
<?php
$mysqli = new Mysqli($servername, $username, $password, $dbname) or die(mysql_error());
$fname = $mysqli->query("SELECT fname FROM student WHERE username = '$user'")->fetch_object()->fname;
print_r($fname);
?>
</div>
<br>
<div>
<label for="sid" accesskey="i">Student ID</label>
<?php
$mysqli = new Mysqli($servername, $username, $password, $dbname) or die(mysql_error());
$sid = $mysqli->query("SELECT sid FROM student WHERE username = '$user'")->fetch_object()->sid;
print_r($sid);
?>
</div>
<br>
<div>
<label for="email" accesskey="E">Email</label>
<?php
$mysqli = new Mysqli($servername, $username, $password, $dbname) or die(mysql_error());
$email = $mysqli->query("SELECT email FROM student WHERE username = '$user'")->fetch_object()->email;
print_r($email);
?>
</div>
<br>
<div>
<label for="phone" accesskey="p">Phone No.</label>
<?php
$mysqli = new Mysqli($servername, $username, $password, $dbname) or die(mysql_error());
$phone = $mysqli->query("SELECT phone FROM student WHERE username = '$user'")->fetch_object()->phone;
print_r($phone);
?>
</div>
<br>
<div>
<label for="sc" accesskey="s">Scolarship</label>
<?php
$mysqli = new Mysqli($servername, $username, $password, $dbname) or die(mysql_error());
$Scolarship = $mysqli->query("SELECT Scolarship FROM student WHERE username = '$user'")->fetch_object()->Scolarship;
print_r($Scolarship);
?>
</div>
</fieldset>
<br >
<fieldset>
<legend><b>Subject Details</b></legend>
<div>
<label for="class" accesskey="c">Subject</label>
<input name="class" type="text" id="class" size="50" required />
</div>
<br>
<div>
<label for="section" accesskey="o">Section</label>
<input name="section" type="number" id="section" min="1" max="9" required />
</div>
<br>
<div>
<label for="semester" accesskey="S">Semester</label>
<select name="semester" id="semester" required="required">
<option value="F15">Fall 2015</option>
<option value="S15">Summer 2015</option>
<option value="SP16">Spring 2016</option>
</select>
</div>
</fieldset>
<br >
<fieldset>
<legend><b>Agreement</b></legend>
<form action="#" onSubmit="if(document.getElementById('agree').checked) { return true; } else { alert('Please indicate that you have agreed on the terms'); return false; }">
<input type="checkbox" name="checkbox" value="check" id="agree" required /> By checking this box, i am fully responsible for the data entered above. I am also providing my official online signature to be liable in however the site may use it for.
<br> <i><font size="2"> * Date and time are recorded for various reasons.</font></i>
<br><br>
<label for="date" accesskey="c">   Current Date & Time : </label>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="Content-Script-Type" content="text/javascript">
<meta name="Content-Style-Type" content="text/css">
<script type="text/javascript">
document.write ('<span id="date-time">', new Date().toLocaleString(), '<\/span>')
if (document.getElementById) onload = function () {
setInterval ("document.getElementById ('date-time').firstChild.data = new Date().toLocaleString()", 50)
}
</script>
</fieldset>
<br>
<input type="submit" class="submit" id="submit" value="Submit" /> <input type="reset" value="Reset"><br>
</form>
</form>
<?php
}
?>
<?php else : ?>
<p>
<span class="error">You are not authorized to access this page.</span> Please <a href="index.php">login</a>.
</p>
<?php endif; ?>
</html>
my functions.php：
<?php
include_once 'psl-config.php';
function sec_session_start() {
$session_name = 'sec_session_id'; // Set a custom session name
$secure = SECURE;
// This stops JavaScript being able to access the session id.
$httponly = true;
// Forces sessions to only use cookies.
if (ini_set('session.use_only_cookies', 1) === FALSE) {
header("Location: ../error.php?err=Could not initiate a safe session (ini_set)");
exit();
}
// Gets current cookies params.
$cookieParams = session_get_cookie_params();
session_set_cookie_params($cookieParams["lifetime"],
$cookieParams["path"],
$cookieParams["domain"],
$secure,
$httponly);
// Sets the session name to the one set above.
session_name($session_name);
session_start(); // Start the PHP session
session_regenerate_id(true); // regenerated the session, delete the old one.
}
function login($email, $password, $mysqli) {
// Using prepared statements means that SQL injection is not possible.
if ($stmt = $mysqli->prepare("SELECT id, username, password, salt
FROM student
WHERE email = ?
LIMIT 1")) {
$stmt->bind_param('s', $email); // Bind "$email" to parameter.
$stmt->execute(); // Execute the prepared query.
$stmt->store_result();
// get variables from result.
$stmt->bind_result($user_id, $username, $db_password, $salt);
$stmt->fetch();
// hash the password with the unique salt.
$password = hash('sha512', $password . $salt);
if ($stmt->num_rows == 1) {
// If the user exists we check if the account is locked
// from too many login attempts
if (checkbrute($user_id, $mysqli) == true) {
// Account is locked
// Send an email to user saying their account is locked
return false;
} else {
// Check if the password in the database matches
// the password the user submitted.
if ($db_password == $password) {
// Password is correct!
// Get the user-agent string of the user.
$user_browser = $_SERVER['HTTP_USER_AGENT'];
// XSS protection as we might print this value
$user_id = preg_replace("/[^0-9]+/", "", $user_id);
$_SESSION['user_id'] = $user_id;
// XSS protection as we might print this value
$username = preg_replace("/[^a-zA-Z0-9_\-]+/",
"",
$username);
$_SESSION['username'] = $username;
$_SESSION['login_string'] = hash('sha512',
$password . $user_browser);
// Login successful.
return true;
} else {
// Password is not correct
// We record this attempt in the database
$now = time();
$mysqli->query("INSERT INTO login_attempts(user_id, time)
VALUES ('$user_id', '$now')");
return false;
}
}
} else {
// No user exists.
return false;
}
}
}
function checkbrute($user_id, $mysqli) {
// Get timestamp of current time
$now = time();
// All login attempts are counted from the past 2 hours.
$valid_attempts = $now - (2 * 60 * 60);
if ($stmt = $mysqli->prepare("SELECT time
FROM login_attempts
WHERE user_id = ?
AND time > '$valid_attempts'")) {
$stmt->bind_param('i', $user_id);
// Execute the prepared query.
$stmt->execute();
$stmt->store_result();
// If there have been more than 5 failed logins
if ($stmt->num_rows > 5) {
return true;
} else {
return false;
}
}
}
function login_check($mysqli) {
// Check if all session variables are set
if (isset($_SESSION['user_id'],
$_SESSION['username'],
$_SESSION['login_string'])) {
$user_id = $_SESSION['user_id'];
$login_string = $_SESSION['login_string'];
$username = $_SESSION['username'];
// Get the user-agent string of the user.
$user_browser = $_SERVER['HTTP_USER_AGENT'];
if ($stmt = $mysqli->prepare("SELECT password
FROM student
WHERE id = ? LIMIT 1")) {
// Bind "$user_id" to parameter.
$stmt->bind_param('i', $user_id);
$stmt->execute(); // Execute the prepared query.
$stmt->store_result();
if ($stmt->num_rows == 1) {
// If the user exists get variables from result.
$stmt->bind_result($password);
$stmt->fetch();
$login_check = hash('sha512', $password . $user_browser);
if ($login_check == $login_string) {
// Logged In!!!!
return true;
} else {
// Not logged in
return false;
}
} else {
// Not logged in
return false;
}
} else {
// Not logged in
return false;
}
} else {
// Not logged in
return false;
}
}
function esc_url($url) {
if ('' == $url) {
return $url;
}
$url = preg_replace('|[^a-z0-9-~+_.?#=!&;,/:%@$\|*\'()\\x80-\\xff]|i', '', $url);
$strip = array('%0d', '%0a', '%0D', '%0A');
$url = (string) $url;
$count = 1;
while ($count) {
$url = str_replace($strip, '', $url, $count);
}
$url = str_replace(';//', '://', $url);
$url = htmlentities($url);
$url = str_replace('&', '&', $url);
$url = str_replace("'", ''', $url);
if ($url[0] !== '/') {
// We're only interested in relative links from $_SERVER['PHP_SELF']
return '';
} else {
return $url;
}
}