用户名实时校验机制-优快云博客

本文链接：https://blog.youkuaiyun.com/digmouse/article/details/3968396

本文介绍了一种基于JavaScript和PHP的用户名实时校验机制。通过客户端JavaScript实现用户名输入后的即时反馈，利用AJAX技术向服务器发送请求，服务器端使用PHP进行数据库查询，判断用户名是否已被注册，并将结果返回给客户端显示。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD> <TITLE> New Document </TITLE> <META NAME="Generator" CONTENT="EditPlus"> <META NAME="Author" CONTENT=""> <META NAME="Keywords" CONTENT=""> <META NAME="Description" CONTENT=""> <mce:script type="text/javascript"></mce:script> </HEAD> <BODY> <form id="form1" name="f1" method="post" action=""> <label>username: <input type="text" name="username" οnblur="checkusername(this.value)"/><div id="checkret"></div> </label> <br/> <label>sex: <input type="text" name="sex"> </label> </form> </BODY> </HTML> register is_registered is_registered check_user check_user $user login

<?php $conn=mysql_connect("localhost","root","") or die("connect db failed"); mysql_select_db("test",$conn); $username=isset($_REQUEST['username'])?$_REQUEST['username']:""; $sql="select username from users where username='".$username."';"; $res=mysql_query($sql); $num=mysql_num_rows($res); if($num==0) { echo "success"; } else { echo "failure"; } exit; ?>

ajax test