我已经创建了一个成功的登录表单，该表单连接到数据库以确定登录是否正确。但我想更新一下，这样如果输入了不正确的用户名或密码，他们就会收到错误消息。我只是不确定如何将其实现到我现有的代码中？。。。
我的用户登录页面：
<form action="../login.php" method="post">
<label for="login-username"><i class="icon-user"></i> <b>Username</b> </label><br/>
<input class="form-control" type="text" name="username">
<br/>
<label for="login-password"><i class="icon-lock"></i> <b>Password</b> </label> <br/>
<input class="form-control" type="password" name="password">
<br/>
<button type="submit" class="btn pull-right">Login</button>
</form>
<?php
if (isset($_SESSION['username'])){
if($_SESSION['logged_in'] = 1){
echo ('Logged in as: '. $_SESSION['username'].' '.$_SESSION['surname']).'<br><a href="logout.php">Log out</a>';
}
}
?>
以及它发布到的login.php：
<?php
session_start();
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "gpdb";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
die("connection failed: " . $conn->connect_error);
}
//echo "connection successful";
$username = $_POST['username'];
$password = $_POST['password'];
$sql = "SELECT * FROM patients where Username ='$username' and Password ='$password'";
$result = $conn->query($sql);
$admin_user = 'admin';
$admin_password = 'admin1';
if ($result->num_rows > 0) {
if ($username === $admin_user || $password === $admin_password ){
foreach($result as $row) {
//echo "PatientID " .$row["PatientID"]."<br>". "First name and Last name: " . $row["Firstname"]. " ".$row["Surname"]. "<br/>";
$_SESSION['id'] = $row["PatientID"];
$_SESSION['username'] = $row["Firstname"];
$_SESSION['surname'] = $row["Surname"];
$_SESSION['logged_in'] = 2;
header("location: http://localhost/index.php");
die;
}
}else{
foreach($result as $row) {
$_SESSION['id'] = $row["PatientID"];
$_SESSION['username'] = $row["Firstname"];
$_SESSION['surname'] = $row["Surname"];
$_SESSION['logged_in'] = 1;
header("location: http://localhost/index.php");
die;
}
}
}else{
$_SESSION['logged_in'] = 0;
header("location: http://localhost/user.php");
die;
}
?>
<?php
if ($result->num_rows > 0){
header("location: http://localhost/index.php");
}else{
echo "Wrong Username or Password <br />".
'<a href="http://localhost/user.php">Go back...</a>';
}
?>
您也可以创建一个login_failure.php页面，然后在其他部分将用户重定向到该页面。或者另一种方法是传递故障消息的值
header("location: http://localhost/user.php?msg = 1");
并在登录框顶部显示该消息。在user.php页面中获取"msg"的值，并应用if条件来显示消息。
<div><?php
$msg = $_GET['msg'];
if (isset($msg)) { echo "Wrong username/password"; } ?> </div>
<form action="../login.php" method="post">
<label for="login-username"><i class="icon-user"></i> <b>Username</b> </label><br/>
<input class="form-control" type="text" name="username">
<br/>
<label for="login-password"><i class="icon-lock"></i> <b>Password</b> </label> <br/>
<input class="form-control" type="password" name="password">
<br/>
<button type="submit" class="btn pull-right">Login</button>
</form>