基于php+ajax的注册用户名验证

服务器端db.php

<?php
 /*数据库连接*/

 $conn=@mysql_connect("localhost","root","");
 mysql_query("SET NAMES UTF8");
 mysql_select_db("php_ajax",$conn);

 //设置页面编码
 header("Content-type:text/html;charset=UTF-8");

 //查询数据库
 if(isset($_GET["username"])){
 $strsql="SELECT * FROM member WHERE username='".unescape($_GET["username"])."'";
 $result=mysql_query($strsql);
 $rows=@mysql_num_rows($result);
 mysql_close($conn);

 //判断是否有此记录
 if($rows){
 echo "已被注册!";
 }else{
 echo "此用户名未被注册!";
 }
 }else{
 echo "别调戏我!";
 }

 /*PHP的unescape转换函数,用来转换Javascript用escape函数加密过的字符
 --此函数需要iconv函数库支持*/

 function unescape($str) {
 $str = rawurldecode($str);
 preg_match_all("/%u.{4}|.{4};|&#\d+;|&#\d+?|.+/U",$str,$r);
 $ar = $r;
 foreach($ar as $k=>$v) {
 if(substr($v,0,2) == "%u")
 $ar[$k] = iconv("UCS-2","UTF-8",pack("H4",substr($v,-4)));
 elseif(substr($v,0,3) == "")
 $ar[$k] = iconv("UCS-2","UTF-8",pack("H4",substr($v,3,-1)));
 elseif(substr($v,0,2) == "&#") {
 $ar[$k] = iconv("UCS-2","UTF-8",pack("n",preg_replace("/[^\d]/","",$v)));
 }
 }
 return join("",$ar);
 }
?>

sql

CREATE TABLE `member` (
 `id` int(11) NOT NULL auto_increment,
 `username` varchar(20) NOT NULL default '',
 `pwd` varchar(50) NOT NULL default '',
 PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=10 DEFAULT CHARSET=utf8 AUTO_INCREMENT=10 ;

--
-- 导出表中的数据 `member`
--

INSERT INTO `member` VALUES (8, 'admin', 'admin888');
INSERT INTO `member` VALUES (9, '测试', '测试');