所以我正在尝试创建一个基本的网站，您可以在其中注册和登录等等。注册很好，它将记录保存在数据库中，如果您拥有正确的用户名和密码，登录就可以了。如果您没有填写所有字段，它会带您回到登录表单.php页面并显示"登录失败！这也行得通，没关系。但是，如果您没有输入正确的信息，它应该只是简单地回显"不正确！出于某种原因，它没有回应我告诉它的内容，它只是进入一个空白的白页。这是登录表单的代码：
<?php
echo include("php_includes/header.php");
?>
<h3 class="first">Member Login</h3>
<form name="loginform" method="post" action="login.php">
<strong></strong><br>
Username: <input name="username" type="text" id="username" /><br><br>
Password: <input name="password" type="password" id="password" /><br><br>
<input type="submit" name="Submit" value="Login" /></form><br>
<a href='register.php'>Register</a>
<?php echo include("php_includes/footer.php");?>
这是实际登录过程的代码：
<?php
session_start();
include ("db_connect.php");
$username = $_POST["username"];
$password = $_POST["password"];
if($username && $password)
{
$password = md5($password);
$queryget = mysql_query("SELECT * FROM users WHERE username='$username' AND password='$password'");
$numrows = mysql_num_rows($queryget) or die(mysql_error());
if($numrows != 0) {//if they can find it in the database
$_SESSION['username'] = $username; //starts the session
header("Location: members.php"); //log in
} else {
echo "Incorrect!";
}
} else {
echo "Login failed!";
include("loginform.php");
}
试试这个：
<?php
session_start();
include ("db_connect.php");
$errors = [];
// Assigning the variables
if ( isset($_POST['username']) && !empty($_POST['username']) ) {
$username = $_POST['username'];
} else {
$errors[] = "Username cannot be blank <br />";
}
if ( isset($_POST['password']) && !empty($_POST['password'])) {
$password = $_POST['password'];
} else {
$errors[] = "Password cannot be blank <br />";
}
if( isset($username) && isset($password) )
{
$password = sha1($password);
$queryget = mysql_query("SELECT * FROM users WHERE username='$username' AND password='$password'");
$numrows = mysql_num_rows($queryget) or die(mysql_error());
if($numrows != 0) {//if they can find it in the database
$_SESSION['username'] = $username; //starts the session
header("Location: members.php"); //log in
exit;
} else {
$error[] = 'Incorrect Username or password';
}
} else {
foreach ($errors as $error) {
echo $error . "<br />";
}
}
希望这有帮助。