AJAX请求未获取任何信息

Question

Here's my PHP file code:

<?php
require('config.inc'); //Init DB.

$current_user_id = $_GET['uid']; //Set User ID From AJAX GET.

mysql_query("USE social-network"); //Set MySQL DB.

$userFavs = "SELECT subscribee_id FROM subscribe WHERE subscriber_id = '" . $current_user_id . "'"; //Get people user is subscribed to.

$query="SELECT * FROM posts WHERE (post_owner_id IN ($userFavs) OR post_owner_id = '" . $current_user_id . "') ORDER BY id DESC"; //Select posts by user AND by people user is subscribed to.

$result=mysql_query($query); //Do the query.

$num=mysql_numrows($result); //Get number of rows in query.

$i=0; //Display selected posts.
while ($i < $num) {

$owner_id=mysql_result($result,$i,"post_owner_id");
$content=mysql_result($result,$i,"content");
$date=mysql_result($result,$i,"date");


$poi_query=mysql_query("SELECT firstname, lastname, profile_picture FROM `social-network`.`users` WHERE id = '" . $owner_id . "'") or die(mysql_error());
$post_firstname=mysql_result($poi_query, 0, "firstname");
$post_lastname=mysql_result($poi_query, 0, "lastname");
$post_profile_picture=mysql_result($poi_query, 0, "profile_picture");
?>

      <div class="post">
        <h1 class="post-title"><a href="profile.php?user=<?php echo $owner_id; ?>"><?php echo $post_firstname; ?> <?php echo $post_lastname; ?></a></h1>
        <p class="content"><?php echo $content; ?></p>
        <p class="details"><?php echo $date; ?></p>

      </div>

      <?php
$i++;
}
?>

Here's my JS AJAX request:

function loadPosts()
{
xmlhttp=new XMLHttpRequest();
xmlhttp.open("GET","PHP/news-feed.php?uid=<?=$current_user_id?>",true);
xmlhttp.send();
document.getElementById("posts").innerHTML=xmlhttp.responseText;
}

Nothing shows up under the posts section on my page. What am I doing wrong? And the PHP code is tested and it worked when I just directly included it in the posts page. What I'm trying to do: PHP Newsfeed with Reload

Answer 1

ID为“ posts”的元素在哪里？，我只能看到带有post class的div标签

Answer 2

One thing that is wrong with your ajax, is that it is assuming to be synchronous: You are expecting a result right after you send your request but instead you should attach an event handler on the onreadystatechange event.

If you don't have any experience with ajax, I would recommend using a library like jQuery to handle that for you.

Apart from that I don't see where you are calling your ajax function either.