index.php：
<?php
session_start();
require 'res/connection.php';
if($_SESSION['id'] !== null){
header("Location: profile.php");
}
?>
<!DOCTYPE html>
<html>
<head>
<title>Welcome to the members section, Login or Register</title>
<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script src="js/fadein.js"></script>
<link rel="stylesheet" type="tex/css" href="css/master.css"/>
<link rel="stylesheet" type="tex/css" href="css/form.css"/>
</head>
<body>
<div class="container loginbdy">
<div class="row">
<div class="col-lg-12 loginform">
<form action="" method="post" class="form">
<h2>Log In :</h2>
<label name="username-label">Username :</label>
<input class="form-control" type="text" placeholder="Your username" name="username" id="username" maxlength="120"/>
<label name="password-label">Password :</label>
<input class="form-control" type="password" placeholder="Your password" name="password" id="password" maxlength="35"/></br>
<input type="submit" class="btn btn-default" value="Log In" name="submit" /></br>
<p>Not a member yet ? <a href="register.php" ><i><b>register</b></i></a></p>
</form>
</div>
<div class="col-lg-3 errorlogin">
<?php
if(isset($_POST['submit'])){
$username = mysqli_real_escape_string($con, $_POST['username']);
$password = mysqli_real_escape_string($con, $_POST['password']);
if(empty($username)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> username is empty.
</div>
';
}elseif(empty($password)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> password is empty.
</div>
';
}else{
$result = mysqli_query($con,"SELECT * FROM `users` WHERE `username` = '$username'");
$row_cnt = mysqli_num_rows($result);
if($row_cnt === 0){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> The username you tried to login with doesn\'t exist, would you like to <a href="register.php">register</a> it ?
</div>
';
}else{
$row = mysqli_fetch_array($result);
$userpassword = $row['password'];
$salt = $row['salt'];
$id = $row['user_id'];
$hashedpassword = crypt($password,$salt);
if($hashedpassword === $userpassword){
$_SESSION['id'] = $id;
echo "
<div class=\"alert alert-success\">
<strong>Session has been set</strong> you are now logged in! your user id is "; echo $_SESSION['id']; echo '
</div>
';
$user_id = mysqli_query($con, "SELECT * FROM `users` WHERE `username` = '$username'");
$row = mysqli_fetch_array($user_id);
$id = $row['user_id'];
$firstname = $row['first name'];
$lastname = $row['last name'];
$semail = $row['email'];
$susername = $row['username'];
$spaid = $row['paid'];
$sdate = $row['date_created'];
$sconfirmed = $row['confirmed'];
$_SESSION['id'] = $id;
$_SESSION['fname'] = $firstname;
$_SESSION['lname'] = $lastname;
$_SESSION['email'] = $semail;
$_SESSION['username'] = $susername;
$_SESSION['paid'] = $spaid;
$_SESSION['date'] = $sdate;
$_SESSION['confirmed'] = $sconfirmed;
header('Location: profile.php');
}else{
echo '
<div class="alert alert-danger">
<strong>Error!</strong> The username or password you entered is incorrect!
</div>
';
}
}
}
}
?>
</div>
</div>
</div>
</body>
</html>
register.php：
<?php
session_start();
require 'res/connection.php';
if($_SESSION['id'] !== null){
header("Location: profile.php");
}
?>
<!DOCTYPE html>
<html>
<head>
<title>Welcome to the members section, Login or Register</title>
<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link rel="stylesheet" type="tex/css" href="css/master.css"/>
<link rel="stylesheet" type="tex/css" href="css/form.css"/>
</head>
<body background="res/background.jpg">
<div class="container">
<div class="row">
<div class="col-lg-9 registerform">
<?php
?>
<form action="" method="post" class="form">
<h2>Register :</h2>
<label name="lname-label">First Name :</label>
<input class="form-control" type="text" placeholder="Your First Name" name="fname" id="fname" maxlength="100" tabindex="1" autofocus />
<label name="lname-label">Last Name :</label>
<input class="form-control" type="text" placeholder="Your Last Name" name="lname" id="lname" maxlength="100" tabindex="2" />
<label name="username-label">Username :</label>
<input class="form-control" type="text" placeholder="Your desired Username" name="username" id="username" maxlength="24" tabindex="3" />
<label name="email-label">Email :</label>
<input class="form-control" type="email" placeholder="Your Email address" name="email" id="email" maxlength="120" tabindex="4" />
<label name="password-label">Password :</label>
<input class="form-control" type="password" placeholder="Your desired password" name="password" id="password" maxlength="35" tabindex="5" />
<label name="repassword-label">re enter Password :</label>
<input class="form-control" type="password" placeholder="Your password again" name="repassword" id="repassword" maxlength="35" tabindex="6" />
<label name="type-label">i am here to :</label></br>
<select name="type" class="form-control" tabindex="7" >
<option>develop websites</option>
<option>hire a developer</option>
</select>
</br>
<input type="submit" class="btn btn-default" value="Register" name="submit" /></br>
<p>already a member ? <a href="index.php" ><i><b>Log In</b></i></a></p>
</form>
</div>
<div class="col-lg-3 errorlog">
<?php
/* if submit button is clicked start the registration */
if(isset($_POST['submit'])){
/* get all the values from the textboxes */
$fname = mysqli_real_escape_string($con,$_POST['fname']);
$lname = mysqli_real_escape_string($con,$_POST['lname']);
$username = mysqli_real_escape_string($con,$_POST['username']);
$email = mysqli_real_escape_string($con,$_POST['email']);
$password = mysqli_real_escape_string($con,$_POST['password']);
$password_verification = mysqli_real_escape_string($con,$_POST['repassword']);
$type = mysqli_real_escape_string($con,$_POST['type']);
$paid = false;
/* form validation */
if(empty($fname)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> first name is empty.
</div>
';
}else if(empty($lname)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> Last name is empty.
</div>
';
}else if(empty($username)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> Username is empty.
</div>
';
}else if(0 === preg_match("/.+@.+\..+/",$email)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> The email you entered is invalid.
</div>
';
}else if(0 === preg_match("/.{6,}/",$password)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> Passwords has to be atleast 6 characters long.
</div>
';
}else if($password !== $password_verification){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> The passwords you entered do not match.
</div>
';
}else if(empty($type)){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> You can be eithere a developer or a host
</div>
';
}else{
$query = "SELECT * FROM users WHERE username = '$username'";
$equery = "SELECT * FROM users WHERE email = '$email'";
if($result = mysqli_query($con,$query)){
$row_cnt = mysqli_num_rows($result);
if($row_cnt > 0){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> This username is already taken!
</div>
';
}else if ($eresult = mysqli_query($con,$equery)){
$erow_cnt = mysqli_num_rows($eresult);
if($erow_cnt > 0){
echo '
<div class="alert alert-danger">
<strong>Error!</strong> This email is already registered!
</div>
';
}else{
$salt = rand(100 , 999) . rand(100 , 999) . rand(1000 , 9999);
$hashedpassword = crypt($password,$salt);
if($type === "develop websites"){
$type="developer";
}else if($type === "hire a developer"){
$type="owner";
}else{
echo'
<div class="alert alert-danger">
<strong>Error!</strong> you can only be an owner or a developer
</div>
';
}
$date = date("m/d/Y h:i:sa");
$confirm = false;
$confirmation_code = rand(100,999) . "-" . rand(100,999);
$insertion = mysqli_query($con,"INSERT INTO `users` (`first name`, `last name`, `email`, `password`, `username`, `salt`, `type`, `paid`, `date_created`, `confirmed`,`confirmation_code`) VALUES ('$fname','$lname','$email','$hashedpassword','$username','$salt','$type','0','$date','$confirm','$confirmation_code')");
if($insertion){
echo "
<div class=\"alert alert-success\">
<strong>Success</strong> your account has been successfully created!
</div>
";
$user_id = mysqli_query($con, "SELECT * FROM `users` WHERE `username` = '$username'");
$row = mysqli_fetch_array($user_id);
$id = $row['user_id'];
$firstname = $row['first name'];
$lastname = $row['last name'];
$semail = $row['email'];
$susername = $row['username'];
$spaid = $row['paid'];
$sdate = $row['date_created'];
$sconfirmed = $row['confirmed'];
$sconfirmation_code = $row['confirmation_code'];
$_SESSION['id'] = $id;
$_SESSION['fname'] = $firstname;
$_SESSION['lname'] = $lastname;
$_SESSION['email'] = $semail;
$_SESSION['username'] = $susername;
$_SESSION['paid'] = $spaid;
$_SESSION['date'] = $sdate;
$_SESSION['confirmed'] = $sconfirmed;
$_SESSION['confirmation_code'] = $sconfirmation_code;
if($user_id){
echo "
<div class=\"alert alert-success\">
<strong>Session has been set</strong> you are now logged in!
</div>
";
echo"<script>
setTimeout(function () {
window.location.href = 'profile.php';},8000);
</script>";
echo "
<div class=\"alert alert-info\">
<strong>Thank you!</strong> in 8 seconds you will be redirected to your new profile
</div>
";
}else{
echo "
<div class=\"alert alert-danger\">
<strong>Failed</strong> your account has been created, but we were unable to log you in, you will have to do this manually <A href=\"index.php\">here</a>
</div>";
}
}else{
echo "
<div class=\"alert alert-danger\">
<strong>Failed</strong> your account has not been created, something went wrong
</div>";
}
}
}
}
}
}
?>
</div>
</div>
</div>
</body>
</html>
现在问题是，一旦你去登录或注册它，检查你是否正在进行会话检查：
if($_SESSION['id'] !== null){
header("Location: profile.php");
}
但是它返回了一个错误说：
注意：未定义的索引：id
我明白错误是因为会话没有设置所以变量$ _SESSION [＆＃39; id＆＃39;]没有设置导致这个错误，我想知道的是，如果有另一种方法来解决这个问题这不包括使用cookie，因为我存储用户信息，并且在这种情况下cookie不安全
我尝试使用session_id（），但无论何时启动会话，都会自动设置session_id（）。因此，即使您未登录
答案 0 :(得分：2)
试试isset： -
if(isset($_SESSION['id'])){
header("Location: profile.php");
}else{
echo 'session is not set';die;
}
答案 1 :(得分：2)
使用isset！
if (isset($_SESSION['id'])) {
// ..
}
Isset会检查var / index是否已定义，因此这对你来说非常合适。
请注意，isset和!empty之间存在差异。 isset仅检查，如果定义了var，!empty会进行更多测试，例如$ var！== false，$ var！== array（），$ var！==＆＃39; 0＆＃39;，$ var！== 0等。
这可能与你的情况无关（除了你有一个允许的id = 0），但总是很有用。
答案 2 :(得分：2)
<?php
Session_start();
if(isset($_SESSION['id'])
Do what you wanna do
?>
您可以使用isset（）查看是否设置了ID。
答案 3 :(得分：0)
if(isset($_SESSION['id'])){
header("location: profile.php");
}
在php中 isset（）用于检查是否设置了ID。