<![CDATA[向东博客 专注WEB应用 构架之美 --- 构架之美，在于尽态极妍 | 应用之美，在于药到病除]]> http://www.jackxiang.com/index.php zh-cn http://www.jackxiang.com/post/1484/ <![CDATA[ajax的基础实例，用于从数据库中检测动态检测用户名是否已经存在]]> jack <xdy108@126.com> Wed, 10 Dec 2008 10:34:37 +0000 http://www.jackxiang.com/post/1484/ test.html
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=utf-8" />
</head>
<script language="javascript">
<!--
function AjaxLib()
{
//创建AJAX实例
try {
     xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
     try {
      xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
     } catch (err) {
      xmlhttp = null;
     }
    }
    if(!xmlhttp && typeof XMLHttpRequest != "undefined")
     xmlhttp = new XMLHttpRequest();
    if (!xmlhttp){
     return null;
    }
    return xmlhttp;
}
function AjaxCheck(obj)
{
//判断检测用户名
var xmlObj  = AjaxLib();
var objId  = obj.id;
var userName = document.getElementById(objId);
var url   = "test.php?userName=" + userName.value;
xmlObj.onreadystatechange = function ()
{
  if (xmlObj.readyState == 4)
  {  
   var objHelpId = document.getElementById("userNameHelp");
   if (xmlObj.responseText == "ok")
   {    
    objHelpId.innerHTML = "可以使用";
   }
   else
   {
    objHelpId.innerHTML = "已经有此用户，请更换一个用户名！";
   }
  }
}
xmlObj.open("GET", url, true);
xmlObj.send(null);
}
-->
</script>
<body>
<form action="" name="f" id="f">
<table border="1" cellspacing="0" width="400" cellpadding="0">
  <tr><td>
   <div>
    <div style="float:left">
     user <input type="text" name="userName" onchange="AjaxCheck(this)" id="userName">
    </div>
    <div id="userNameHelp" style="color:red; float:right">
    </div>
   </div>  
  </td></tr>
  <tr><td>password <input type="text" name="userPassword" id="userPassword"></td></tr>
</table>
</form>
</body>
</html>


test.php


<?php
/**
* ajax判断异步判断用户名
*
* 数据库：user; 表：user;
*
*/
//header("Content-Type: text/html; charset=UTF-8\n");
//echo "<meta http-equiv='content-type' content='text/html;charset=utf-8'>";
$link = mysql_connect("localhost", "root", "");  //连接数据库
mysql_select_db("user");       //打开数据库
mysql_query("set names 'utf8'");     //设置字符集
$userName = isset($_GET["userName"]) ? $_GET["userName"] : ""; //取得URL后要检测的用户名
//$userName = "袁相宜";
$userName = iconv("GB2312", "UTF-8", $userName); //把接收的值转换成utf8码
if (empty($userName))        //判断是否是空值
{
echo "fail"
exit();
}
$sql = "SELECT * FROM user WHERE userName = '{$userName}'";
$result = mysql_query($sql, $link);
if (mysql_num_rows($result) > 0)
{
$tip = "fail";
}
else
{
$tip = "ok";
}
echo($tip);
exit(0);
?>




]]> http://www.jackxiang.com/post/1484/#blogcomment51630 <![CDATA[[评论] ajax的基础实例，用于从数据库中检测动态检测用户名是否已经存在]]> 123 <user@domain.com> Tue, 17 Aug 2010 07:44:23 +0000 http://www.jackxiang.com/post/1484/#blogcomment51630