PHP实现简单注册登录系统

<form action="login_process.php" method="POST">
 登录
 <input type="text" name="userName" size="20" maxlength="15" placeholder="请填写用户名及域名">
 <br>

 注册
 <input type="password" name="password" size="20" maxlength="15">
 <br>
 <input type="submit" value="登录">
 <input type="button" onclick="window.location.href='register.html'" value="注册">
</form>

<h2>用户注册登录系统</h2>
<hr>
<form action="register.php" method="POST" enctype="multipart/form-data">
 用户名：
 <input type="text" name="userName" size="20" maxlength="15" placeholder="必须填写用户名">
 @
 <select name="domain" id="">
 <option value="@163.com" selected>163.com</option>
 <option value="@126.com">126.com</option>
 </select>
 <br>

 登录密码：
 <input type="password" name="password" size="20" maxlength="15">
 <br>
 
 确认密码：
 <input type="password" name="confirmPassword" size="20" maxlength="15">
 <br>

 选择性别：
 <input type="radio" name="sex" value="male" checked>男
 <input type="radio" name="sex" value="female">女
 <br>

 个人爱好：
 <input name="interests[]" type="checkbox" value="music">音乐
 <input name="interests[]" type="checkbox" value="game">游戏
 <input name="interests[]" type="checkbox" value="film">电影
 <br>

 个人相片
 <input type="hidden" name="MAX_FILE_SIZE" value="1024">
 <input type="file" name="myPicture" size="25" maxlength="100">
 <br>

 备注信息：
 <textarea name="remark" cols="30" rows="4" placeholder="请填写备注信息"></textarea>
 <br>

 <input type="submit" name="submit" value="注册">
 <input type="reset" name="cancel" value="重填">
</form>

<?php
 include_once("function/database.php");
 // $userName = $_POST['userName'];
 // $password = $_POST['password'];
 $userName = addslashes($_POST['userName']);
 $password = addslashes($_POST['password']);
 getConnect();
 $loginSQL = "select * from users where userName='$userName' and password='$password'";
 echo $loginSQL;
 $resultLogin = mysql_query($loginSQL);
 if (mysql_num_rows($resultLogin) > 0) {
 echo "登录成功";
 } else {
 echo "登录失败";
 }
 closeConnect();
?>

<?php
 include_once("function/fileSystem.php");
 include_once("function/database.php");

 if (empty($_POST)) {
 exit("您提交的表单数据超过post_max_size! <br>");
 }

 // 判断输入密码与确认密码是否相同
 $password = $_POST['password'];
 $confirmPassword = $_POST['confirmPassword'];
 if ($password != $confirmPassword) {
 exit("输入的密码与确认密码不相等！");
 }

 $userName = $_POST['userName'];
 $domain = $_POST['domain'];
 $userName = $userName . $domain;

 // 判断用户名是否重复
 $userNameSQL = "select * from users where userName = '$userName'";
 getConnect();
 $resultSet = mysql_query($userNameSQL);
 if (mysql_num_rows($resultSet) > 0) {
 exit("用户名已被占用，请更换其他用户名");
 }

 $sex = $_POST['sex'];
 if (empty($_POST['interests'])) {
 $interests = "";
 } else {
 $interests = implode(";", $_POST['interests']);
 }

 $remark = $_POST['remark'];
 $myPictureName = $_FILES['myPicture']['name'];

 $registerSQL = "insert into users values(null, '$userName', '$password', '$sex', '$interests', '$myPictureName', '$remark')";
 $message = upload($_FILES['myPicture'], "uploads");

 if ($message == "上传成功" || $message == "没有上传") {
 mysql_query($registerSQL);
 $userID = mysql_insert_id();
 echo "注册成功<br>";
 } else {
 exit($message);
 }

 $userSQL = "select * from users where user_id = '$userID'";
 $userResult = mysql_query($userSQL);
 if ($user = mysql_fetch_array($userResult)) {
 echo "您的注册用户名为：" . $user['userName'];
 } else {
 exit("用户注册失败！");
 }
 closeConnect();

<?php
 $databaseConnection = null;
 function getConnect() {
 $hosthome = "localhost";
 $database = "register";
 $userName = "root";
 $password = "123456";
 global $databaseConnection;
 $databaseConnection = @mysql_connect($hosthome, $userName, $password) or die (mysql_error());
 mysql_query("set names gbk");
 @mysql_select_db($database, $databaseConnection) or die (mysql_error());
 }
 
 function closeConnect() {
 global $databaseConnection;
 if ($databaseConnection) {
 @mysql_close($databaseConnection) or die (mysql_error());
 }
 }
?>

<?php
 function upload($file, $filePath) {
 $error = $file['error'];
 switch ($error) {
 case 0:
 $fileName = $file['name'];
 $fileTemp = $file['tmp_name'];
 $destination = $filePath . "/" . $fileName;
 move_uploaded_file($fileTemp, $destination);
 return "上传成功";
 case 1:
 return "上传超过upload_max_filesize";
 case 2:
 return "上传文件超过form的MAX_FILE_SIZE";
 case 3:
 return "附件部分上传";
 case 4:
 return "没有上传";
 }
 }
?>