jQuery PHP:检查用户名是否已经存在

I'm trying to check the existence of an username already registered on my application using jQuery+Ajax+POST.

我正在尝试使用jQuery+Ajax+POST检查应用程序上已经注册的用户名是否存在。

HTML

HTML

<div class="form-group">
    <label for="username" class="col-md-3 control-label">Username</label>
    <div class="col-md-9">
        <input type="text" id="username" class="form-control" name="username" placeholder="Username">
    </div>
</div>
<div class="col-sm-9 col-sm-offset-3" id="userCheck">
    <div class="alert alert-info" id="userCheckLabel"></div>
</div>

jQuery

jQuery

$('#username').focusout(function() {
    var username = $('#username').val();
    checkUserExist(username);
})
function checkUserExist($uname) {
    $.post( "../core/lib/checkUserExist.php", function( data ) {
    if(data.html == 'true') {
       $('#userCheck').slideDown("slow");
       $('#userCheckLabel').text("This user already exist!")
    }
});

PHP

PHP

<?php
require_once('../../core/class.user.php');
$user = new USER();
$uname = $_POST['username'];

$stmt = $user->runQuery("SELECT user_nameFROM users WHERE user_name=:uname ");
$stmt->execute(array(':uname'=>$uname));
$row=$stmt->fetch(PDO::FETCH_ASSOC);

if($row['user_name']==$uname) {
    print 'true';
} else {
    print 'false';
}
?>

I Don't include class.user.php cause It's only handling the PDO Connection, If I remove the if(data.html == 'true') the connection work as expected and the message come out.

我不包括class.user。php因为它只处理PDO连接，如果我删除If(数据)。连接按预期工作，消息出来。

Behavior

行为

The code work if I remove the if(data.html == 'true'). but with this it doesn't do anything, no errors in console. So I think the error is in the way I handle the PHP part. Any suggestion?

如果我删除if(数据)，代码就可以工作。html = =“真正的”)。但是它不会做任何事情，在控制台没有错误。我认为错误在于我处理PHP部分的方式。任何建议吗?

1 个解决方案

#1

Since you are returning string not HTML, so you have to do like below:-

因为你是返回字符串而不是HTML，所以你必须做如下:-

$.post( "../core/lib/checkUserExist.php",{username: uname }, function( data ) {
     console.log(data);// check this and let me know the output
     if(data == 'true') {  // or try if(data)
       $('#userCheck').slideDown("slow");
       $('#userCheckLabel').text("This user already exist!")
    }
});