我是PHP的新手。我正在尝试登录，但它总是给我以下消息：
"用户名或密码无效，请重试"。
如果有人能帮助我，我将不胜感激。
<?php
$errors = array(
1=>"Invalid user name or password, Try again",
2=>"Please login to access this area"
);
$error_id = isset($_GET['err']) ? (int)$_GET['err'] : 0;
if ($error_id == 1) {
echo '<p class="text-danger">'.$errors[$error_id].'</p>';
} elseif ($error_id == 2) {
echo '<p class="text-danger">'.$errors[$error_id].'</p>';
}
?>
<h2 id="loginfont">Login Page</h2>
<br/><br/>
<fieldset style="font-family: Arial; background-color: lightblue; color: rgb(0,0,100)">
<legend style="font-variant: small-caps; font-weight:bold"> Login Form </legend>
<form name="LoginForm" method="POST" action="authenticate.php">
<label style="position: relative; line-height: 2; margin: 10px 0px"> Username: <input placeholder="Type K-number" style="position: absolute; margin-left: 20px; width: 15am; left: 80px" type="text" name="username" /> <span style="color: red">*</span> </label> <br/>
<label style="position: relative; line-height: 2; margin: 10px 0px"> Password: <input type="password" placeholder="Type Password" style="position: absolute; margin-left: 20px; width: 15am; left: 80px" type="text" name="password" /> <span style="color: red">*</span> </label> <br/>
<input type="submit" value="Login" /> <input type="reset" />
</fieldset>
</form>
这是我的身份验证.php代码：
<?php
require 'database.php';
session_start();
$username = "";
$pass = "";
if(isset($_POST['username'])){
$username = $_POST['username'];
}
if (isset($_POST['password'])) {
$password = $_POST['password'];
}
echo $username ." : ".$password;
$q = 'SELECT * FROM username WHERE username=:username AND password=:password';
$query = $db->prepare($q);
$query->execute(array(':username' => $username, ':password' => $password));
if($query->rowCount() == 0){
header('Location: index.php?err=1');
}else{
$row = $query->fetch(PDO::FETCH_ASSOC);
session_regenerate_id();
$_SESSION['sess_user_id'] = $row['id'];
$_SESSION['sess_username'] = $row['username'];
$_SESSION['sess_userrole'] = $row['role'];
echo $_SESSION['sess_userrole'];
session_write_close();
if( $_SESSION['sess_userrole'] == "0"){
header('Location: adminpage.php');
}else{
header('Location: studentpage.php');
}
}
?>
尝试将查询行替换为以下内容：
$q = "SELECT * FROM username WHERE username='$username' AND password='$password'";
问题可能是因为用户名和密码两边缺少单引号。看起来您正在生成的实际查询目前如下所示，因此它不知道 jsmith 和 hello123 是什么：
SELECT * FROM username WHERE username=jsmith AND password=hello123;