您好我试图让我的注册页面检查用户名或电子邮件是否已被使用。但它只是代码而不是它们，而在你将它标记为Check if username already exists using PHP之前，我已经去了那里，我尝试了修复它们但我没有做到这一点这一点，我一无所知，我已经尝试了所有我知道的事情！
注册页面的HTML
<?php
session_start();
include 'header.php';
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
if (strpos($url, 'error=username') !== false) {
echo "<div class='transition' style='height: 20px; background-color: #ff6b66; text-align: center; margin-top: 30px; margin-right: 40%; margin-left: 40%; border-radius: 20px; padding: 5px;'>Fill out username box!</div>";
}
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
if (strpos($url, 'error=password') !== false) {
echo "<div class='transition' style='height: 20px; background-color: #ff6b66; text-align: center; margin-top: 30px; margin-right: 40%; margin-left: 40%; border-radius: 20px; padding: 5px;'>Fill out password box!</div>";
}
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
if (strpos($url, 'error=first') !== false) {
echo "<div class='transition' style='height: 20px; background-color: #ff6b66; text-align: center; margin-top: 30px; margin-right: 40%; margin-left: 40%; border-radius: 20px; padding: 5px;'>Fill out First Name box!</div>";
}
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
if (strpos($url, 'error=last') !== false) {
echo "<div class='transition' style='height: 20px; background-color: #ff6b66; text-align: center; margin-top: 30px; margin-right: 40%; margin-left: 40%; border-radius: 20px; padding: 5px;'>Fill out Last Name box!</div>";
}
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
if (strpos($url, 'error=email') !== false) {
echo "<div class='transition' style=' transition-delay: 1s;box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2); height: 20px; background-color: #ff6b66; text-align: center; margin-top: 30px; margin-right: 40%; margin-left: 40%; border-radius: 20px; padding: 5px;'>Fill out Email box!</div>";
}
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
if (strpos($url, 'error=user_name_taken') !== false) {
echo "<div class='transition' style='height: 20px; background-color: #ff6b66; text-align: center; margin-top: 30px; margin-right: 40%; margin-left: 40%; border-radius: 20px; padding: 5px;'>This username is already in use!</div>";
}
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
if (strpos($url, 'error=user_email_taken') !== false) {
echo "<div class='transition' style='height: 20px; background-color: #ff6b66; text-align: center; margin-top: 30px; margin-right: 40%; margin-left: 40%; border-radius: 20px; padding: 5px;'>This email is already in use!</div>";
}
if (isset($_SESSION['id']) !== true) {
header('Location: ../login.php');
}
?>
<html>
<head>
<title>Add Teacher</title>
<link rel="stylesheet" type="text/css" href="../assets/css/adduser.css">
</head>
<body>
<div class="loginbox">
<h1 class="longintitle" style="font-family: Tahoma;">Add Teacher</h1>
<form class="form" action="../includes/adduser.php" method="post" enctype="multipart/form-data">
<input autocomplete="off" placeholder="Username" name="username" type="text" >
<input autocomplete="off" placeholder="Password" name="password" type="password">
<input autocomplete="off" placeholder="First Name" name="first" type="text">
<input autocomplete="off" placeholder="Last Name" name="last" type="text">
<input autocomplete="off" placeholder="Email" name="email" type="email">
<input class="loginbutton" name="create" type="submit" value="Create">
</form>
<p>Students will be in beta copie THIS IS ALPHA</p>
</div>
</body>
</html>
php for it
<?php
session_start();
include_once("../includes/db.php");
$id = $_POST['id'];
$username = $_POST['username'];
$password = $_POST['password'];
$first = $_POST['first'];
$last = $_POST['last'];
$email = $_POST['email'];
if (empty($username)) {
header('Location: ../teacher/adduser.php?error=username');
exit();
}
if (empty($password)) {
header('Location: ../teacher/adduser.php?error=password');
exit();
}
if (empty($first)) {
header('Location: ../teacher/adduser.php?error=first');
exit();
}
if (empty($last)) {
header('Location: ../teacher/adduser.php?error=last');
exit();
}
if (empty($email)) {
header('Location: ../teacher/adduser.php?error=email');
exit();
} else {
$sql = "SELECT * FROM user WHERE username='".$username."'";
$result = mysqli_query($conn, $sql);
$usernamecheck = mysql_num_rows($result);
if ($usernamecheck > 0) {
header('Location: ../teacher/adduser.php?error=user_name_taken');
exit();
}
$sql = "SELECT * FROM user WHERE email='$email'";
$result = mysqli_query($conn, $sql);
$emailtaken = mysql_num_rows($result);
if ($emailtaken > 0) {
header('Location: ../teacher/adduser.php?error=user_email_taken');
exit();
} else {
$sql = "INSERT INTO user (id, username, password, first, last, email) VALUES ('$id', '$username', '$password', '$first', '$last', '$email')";
$result = mysqli_query($conn, $sql);
header('Location: ../teacher/adduser.php');
}
}
?>
如果需要，但是怀疑它是什么＆＃34; db.php
<?php
$conn = mysqli_connect("localhost", "dbuser", "dbpass", "dbmain");
if (!@mysqli_connect("localhost", "dbuser", "dbpass", "dbmain")) {
echo "<div style=' box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2); padding: 3px; background-color: red; height: 20px;'><h3 style='text-align: center;'>Cannot connect to database have the admin take a look!</h3></div>";
die(mysql_error());
}
else {
echo "<div style=' box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2); padding: 3px; background-color: lightgreen; height: 20px;'><h3 style='text-align: center;'>Connected to database Successfully!</h3></div>";
}
?>
请帮助我不知道如何解决这个问题！如果您需要更多信息，请询问。
提前致谢！
答案 0 :(得分：0)
当你使用mysqli时，我认为你可能需要用mysql i _num_rows替换mysql_num_rows。 （缺少＆＃39;我在mysqli_num_rows中）。
答案 1 :(得分：-1)
替换＆＃34; mysql_num_rows＆＃34;用＆＃34; mysqli_num_rows＆＃34; ，同时获取行。因为$ conn是一个＆＃34; mysqli_connect＆＃34;实例