html代码如下
<form action="" method="get">
用户名:<input type="text"id="userName" name="userName">
<button id="judge">检测用户名</button>
<div id="show"></div>
</br>
密 码:<input type="password" name="password"></br>
<input type="submit" id="btn" name="sub" value="注册"></br>
</form>
js代码如下
$(document).ready(function(){
$("#judge").on("click",function(){
var userName = $('#userName').val();
var changeUrl = "GradeAdmin.php?action=check&userName="+userName;
if($.trim(userName) == ""){ //用户名不能为空
alert("用户名不能为空");
}
else{
//后台验证
$.get(changeUrl,null,function(data){
if(data==1){
alert("以被占用");
}else{
alert("可以用");
}
});
};
});
});
php代码如下:
if(true){
$conn = mysql_connect("localhost", "root", "");
$userName = $_GET['userName'];
if ($conn) {
mysql_select_db("myapp", $conn);
$judge = mysql_query("SELECT * FROM uesrs WHERE `name` = '$userName'");
$j = mysql_num_rows($judge);
if ($j==1) {
echo 1;
} else {
echo 0;
}
}
exit();
}