声明:本程序纯粹是本人在学习过程中突发奇想做的，并未考虑任何可行性，实用性，只是留下来供以后参考。
前端页面
sign.html
<!DOCTYPE html><html> ???<head> ???????<meta charset=‘utf-8‘> ???????<title>QQ注册&登录</title> ???????<link rel=‘stylesheet‘ type=‘text/css‘ href=‘./sign.css‘> ???????<script src="http://cdn.bootcss.com/blueimp-md5/1.1.0/js/md5.js"></script> ???????<script src=‘./sign.js‘ type=‘text/javascript‘> </script> ????</head> ???<body> ???????<div class=‘header‘>QQ注册&登录</div> ???????<div class=‘container‘> ???????<h3>注册</h3> ???????<form name=‘signup‘ action=‘./signup.php‘ onsubmit=‘return validateForm1()‘ method=‘post‘> ???????????QQ:<input type=‘text‘ name=‘uid‘ id=‘userid1‘> ???????????密码:<input type=‘password‘ name=‘upd‘ id=‘userpassword1‘> ???????????<input type=‘submit‘ onsubmit="" value=‘注册‘> ???????</form> ???????<h3>登录</h3> ???????<form name=‘signin‘ action=‘./signin.php‘ onsubmit=‘return validateForm2();‘ method=‘post‘> ???????????QQ:<input type=‘text‘ name=‘uid‘ id=‘userid2‘> ???????????密码:<input type=‘password‘ name=‘upd‘ id=‘userpassword2‘> ???????????<input type=‘submit‘ onsubmit="" value=‘登录‘> ???????</form> ???????</div> ???</body></html>
CSS
sign.css
* { ???margin: 0 0 0 0; ???padding: 0 0 0 0;}body { ???background:whitesmoke; ???font-size: 1em;}.header { ???height:3em; ???font-size: 2.5em; ???line-height: 3em; ???color:gray; ???border-bottom:solid black 1px; ???text-align: center;}.container { ???text-align: center;}JS
sign.js
function validateForm1(){ ???var id = this[‘userid1‘].value; ???var password = this[‘userpassword1‘].value; ???if ( !id.match(/^\d{5,10}$/) ) { ???????????alert (‘ID必须为5至10位数字‘); ???????????return false; ???????} ???if ( !password.match(/^[\d\w]{6,18}$/) ) { ???????????alert (‘密码必须为6至32位数字和（或）字母‘); ???????????return false; ???????} ???this[‘userpassword1‘].value = ?md5(password);}function validateForm2(){ ???var id = this[‘userid2‘].value; ???var password = this[‘userpassword2‘].value; ???if ( !id.match(/^\d{5,10}$/) ) { ???????????alert (‘ID必须为5至10位数字‘); ???????????return false; ???????} ???if ( !password.match(/^[\d\w]{6,18}$/) ) { ???????????alert (‘密码必须为6至18位数字和（或）字母‘); ???????????return false; ???????} ???this[‘userpassword2‘].value = ?md5(password);}服务器端脚本
signin.php
<?php$uid = $_POST[‘uid‘];$upd = $_POST[‘upd‘];$upd = md5($upd);$conn = mysqli_connect(‘localhost‘, ‘myqq‘, ‘myqq‘, ‘qq‘);if (!$conn){ ???die ("数据库连接失败" . mysqli_connect_error());}$sql_select = <<<EOFselect id,password from user where id = ‘$uid‘EOF;$result = $conn->query($sql_select);if ( $result->num_rows == 1){ ???//echo ‘用户存在‘; ???$dbupd = ($result->fetch_assoc())[‘password‘]; ???if ( $dbupd == $upd ){ ???????echo "登录成功"; ???} ???else { ???????echo "密码错误"; ???????//echo "<br>" . $upd . "<br>" . $dbupd; ???} ???}else { ???echo "用户不存在";}?>signup.php
<?php$uid = $_POST[‘uid‘];$upd = $_POST[‘upd‘];$upd = md5($upd);//echo $upd . ‘<br>‘;//echo $uid . $upd;$conn = mysqli_connect( ‘localhost‘, ‘myqq‘, ‘myqq‘, ‘qq‘ );if (!$conn){ ???die ("数据库连接失败" . mysqli_connect_error() );} $sql_select = <<<EOFselect id,password from user where id = ‘$uid‘EOF;//echo $sql_select;$result = $conn->query( $sql_select ) ;if ( $result->num_rows <= 0){ ???$sql_insert = <<<EOFinsert into user values($uid, ‘$upd‘)EOF; ???if ( $conn->query($sql_insert) === TRUE ) ???{ ???????echo ‘注册成功‘; ???} ???else { ???????echo "注册失败，请重试" . $sql . ‘<br>‘ . $conn->error; ???}}else { ???echo "用户已存在";}$conn-close();?>用PHP&JS实现的ID&密码校验程序
原文地址：https://www.cnblogs.com/liupy/p/9165215.html