我花了最后一个半小时查看这段代码，但我无法弄清楚出了什么问题。它不会返回任何错误，并且使用查询调用的 while 循环工作正常，但mysql_num_rows将不起作用。
在我阅读代码之前，我想让你知道我已经尝试删除查询中的所有额外混乱，例如Order By但它仍然抛出警告。
守则：
<?php
global $_SESSION,$os_DB,$ui,$count;
//Loggedin
if($_SESSION['login']!=1)
{
print "You must be logged in.";
include($root . 'footer.php');
exit;
}
//Check banned account
elseif($ui['level']=="2"){
print "Sorry but your account is banned.";
include($root . 'footer.php');
exit;
}
//Check email verified
elseif($ui['email_check']=="0"){
print "Sorry but your account has not been verified, to verify your account now please visit <a href='index.php?index=verify&email=".$ui['email']."'>THIS LINK</a>.";
include($root . 'footer.php');
exit;
}
date_default_timezone_set('America/New_York');
$country= $ui['country'];
$dates=mysql_query("SELECT * FROM `contest` WHERE `countries` LIKE '%$country%'");
$timestamp = time();
$getcontests = $os_DB->query("SELECT * FROM contest WHERE date_1 <= '$timestamp' AND date_2 >= '$timestamp' AND countries LIKE '%$country%'");
$num = $os_DB->num($getcontests);
if($num == 0){
print"<td colspan='4'>There are currently no active contests</td>";
}
else
{
while ($dat = mysql_fetch_array($dates)) {
$tname = preg_replace('/s+/', '', $dat['name']);
///////////Problem Area vvvv////////////////////////
$places="(SELECT * FROM `".$tname."_contest` WHERE `username` <> 'admin' AND `completed` >= '".$dat['min_offers']."' ORDER BY `completed` DESC LIMIT ".$dat['rewards'].")";
$results=mysql_query($places) or die(mysql_error());
if ($dat['rewards'] == 1){
$reward = "".$dat['reward_1']."";
}
else if ($dat['rewards'] == 2){
$reward = "".$dat['reward_1'].",".$dat['reward_2']."";
}
else if ($dat['rewards'] == 3){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3']."";
}
else if ($dat['rewards'] == 4){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3'].",".$dat['reward_4']."";
}
else if ($dat['rewards'] == 5){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3'].",".$dat['reward_4'].",".$dat['reward_5']."";
}
else if ($dat['rewards'] == 6){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3'].",".$dat['reward_4'].",".$dat['reward_5'].",".$dat['reward_6']."";
}
else if ($dat['rewards'] == 7){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3'].",".$dat['reward_4'].",".$dat['reward_5'].",".$dat['reward_6'].",".$dat['reward_7']."";
}
else if ($dat['rewards'] == 8){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3'].",".$dat['reward_4'].",".$dat['reward_5'].",".$dat['reward_6'].",".$dat['reward_7'].",".$dat['reward_8']."";
}
else if ($dat['rewards'] == 9){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3'].",".$dat['reward_4'].",".$dat['reward_5'].",".$dat['reward_6'].",".$dat['reward_7'].",".$dat['reward_8'].",".$dat['reward_9']."";
}
else if ($dat['rewards'] == 10){
$reward = "".$dat['reward_1'].",".$dat['reward_2'].",".$dat['reward_3'].",".$dat['reward_4'].",".$dat['reward_5'].",".$dat['reward_6'].",".$dat['reward_7'].",".$dat['reward_8'].",".$dat['reward_9'].",".$dat['reward_10']."";
}
$rewardsa = explode(",", $reward);
$i=0;
$a=1;
// Offers Contest
if(time() <= $dat['date_2'] && time() >= $dat['date_1'] && $dat['type'] == offer) {
print" <table width ='100%'><tr><th align='center'><font size='4'>{$dat['name']}</font></th><th align='right'><font size='1'>".date("m/d/Y h:i A", $dat['date_1'])."-".date("m/d/Y h:i A", $dat['date_2'])."</font></th></tr></table><br />".$dat['desc']."<br /><font size='1' color='white'>You must complete offers worth at least ".$dat['min_points']." points or $".$dat['min_cash']." to count towards contest!<br /><br />
You must also complete at least ".$dat['min_offers']." offers in order to be eligible for winnings.</font><br /><br />";
print" <table width ='100%'><tr><th align='left'>Place</th><th align='center'>User</th><th align='right'>Prize</th><th align='right'>Completed</th></tr>";
if(mysql_num_rows($results == 0)){
if($dat['r_type'] == points){
print" <tr><td align='left'>{$a}</td><td align='center'>......</td><td align='right'>{$rewardsa[$i]} points</td><td align='right'>--</td></tr>";
}
if($dat['r_type'] == cash){
print" <tr><td align='left'>{$a}</td><td align='center'>......</td><td align='right'>$".$rewardsa[$i]."</td><td align='right'>--</td></tr>";
}
$i++;
$a++;
}
while ($place = mysql_fetch_array($results)) {
if($dat['r_type'] == points){
print" <tr><td align='left'>{$a}</td><td align='center'>{$place['username']}</td><td align='right'>{$rewardsa[$i]} points</td><td align='right'>{$place['completed']}</td></tr>";
}
if($dat['r_type'] == cash){
print" <tr><td align='left'>{$a}</td><td align='center'>{$place['username']}</td><td align='right'>$".$rewardsa[$i]."</td><td align='right'>{$place['completed']}</td></tr>";
}
$i++;
$a++;
}
}
}
}
?>
</table>
将
代码中的mysql_num_rows($results == 0)替换为mysql_num_rows($results) == 0
你应该改用mysql_num_rows($results) == 0。
if(mysql_num_rows($results == 0)){
应该是
if(mysql_num_rows($results) == 0){