PHP受影响的行= 1将无法正常工作

<?php
ob_start();
header("Cache-Control: no-cache,must-revalidate"); // HTTP/1.1
header("Expires: Sat,26 Jul 1997 05:00:00 GMT"); // Date in the past
header('Content-type: text/html; charset=utf-8');
include "tilslut.php";
$userid = $_GET["userid"];
$s = mysql_query("SELECT points,lastpoint FROM member_profile WHERE user_id = '".$userid."'");
$n = mysql_fetch_array($s);
$tid = time(); 
mysql_query("UPDATE member_profile set points = points+1,lastpoint=$tid  WHERE lastpoint<=$tid-60 AND user_id = '".$userid."'");
$e = mysql_query("SELECT points FROM member_profile WHERE user_id = '".$userid."'");
$f = mysql_fetch_array($e); 
if (mysql_affected_rows() == 1) {
$s = mysql_query("SELECT points FROM member_profile WHERE user_id = '".$userid."'");
$n = mysql_fetch_array($s);
?>
Inserted!
<?
}else{
echo "Already got";
}
ob_flush();
?>

我有这个给点.
更新查询有效,并且仅在lastpoint< = time() - 60时给出点,但即使它没有插入,它仍然会说“已插入”.
我曾尝试使用受mysql影响的行来检查它是否有影响,但这似乎不起作用.