在我的 JavaScript 长轮询脚本中，我调用 msgsrv.php 来回num_rows显屏幕上的 not。这是正在运行的JavaScript：
<script type="text/javascript" charset="utf-8">
function addmsg(type, msg){
/* Simple helper to add a div.
type is the name of a CSS class (old/new/error).
msg is the contents of the div */
$("#notiWrap.notiZero").html(
"<div id='notiZero "+ type +"'>"+ msg +"</div>"
);
}
function waitForMsg(){
/* This requests the url "msgsrv.php"
When it complete (or errors)*/
$.ajax({
type: "GET",
url: "http://mediahood.net/widgets/txtr/inc/msgsrv.php",
async: true, /* If set to non-async, browser shows page as "Loading.."*/
cache: false,
timeout:50000, /* Timeout in ms */
success: function(data){ /* called when request to barge.php completes */
addmsg("notiMsg", data); /* Add response to a .msg div (with the "new" class)*/
setTimeout(
waitForMsg, /* Request next message */
1000 /* ..after 1 seconds */
);
},
});
};
$(document).ready(function(){
waitForMsg(); /* Start the inital request */
});
</script>
但是，msgsrv.php 知道数据库中实际的最新行，但它现在不知道页面上加载的最新行的 id。$num_rows 有效；$loaded_rows 失败。$loaded_rows 失败，因为当 JS 调用 msgsrv.php 时，它会重置为数据库的实际 num_rows。我需要 PHP 来读取页面上而不是数据库中的 $loaded_rows 是什么，因为我已经知道如何查询最新的行。
这是我的 msgsrv.php：
<?php
/* Send a string after a random number of seconds (2-10) */
sleep(2);
include('/home/alimix/public_html/include/conn.php');
/* Variables */
$nr = mysql_query("SELECT * FROM txtr");
while(mysql_fetch_array($nr))
{$nowrecent = mysql_num_rows($nr);}
$mr = mysql_query("SELECT * FROM txtr ");
for( $i=0; $i < 1; $i++ )
{$mostrecent = "$nowrecent";}
/* $mostrecent shouldn't equal $nowrecent if new rows aren't loaded*/
$minus = $nowrecent - $mostrecent;
if ($minus > 0) {
//echo $nowrecent;
echo $minus;
//echo $mostrecent;
}
elseif($minus < 1) {
echo "nr".$nowrecent."";
echo " ";
echo "mr".$mostrecent."";
}
?>