我在about.com上找到了这个脚本,我正在尝试学习如何创建评级系统,但脚本给了我一个警告,我在下面列出。
我想知道如何解决这个问题?我需要改变哪些代码以及在哪里?
以下是警告。
Warning: Division by zero on line 43
以下是以下脚本。
<?php
// Connects to your Database
mysql_connect("localhost", "root", "", "sitename") or die(mysql_error());
mysql_select_db("sitename") or die(mysql_error());
//We only run this code if the user has just clicked a voting link
if ( $mode=="vote")
{
//If the user has already voted on the particular thing, we do not allow them to vote again $cookie = "Mysite$id";
if(isset($_COOKIE[$cookie]))
{
Echo "Sorry You have already ranked that site <p>";
}
//Otherwise, we set a cooking telling us they have now voted
else
{
$month = 2592000 + time();
setcookie(Mysite.$id, Voted, $month);
//Then we update the voting information by adding 1 to the total votes and adding their vote (1,2,3,etc) to the total rating
mysql_query ("UPDATE vote SET total = total+$voted, votes = votes+1 WHERE id = $id");
Echo "Your vote has been cast <p>";
}
}
//Puts SQL Data into an array
$data = mysql_query("SELECT * FROM vote") or die(mysql_error());
//Now we loop through all the data
while($ratings = mysql_fetch_array( $data ))
{
//This outputs the sites name
Echo "Name: " .$ratings['name']."<br>";
//This calculates the sites ranking and then outputs it - rounded to 1 decimal
$current = $ratings[total] / $ratings[votes];
Echo "Current Rating: " . round($current, 1) . "<br>";
//This creates 5 links to vote a 1, 2, 3, 4, or 5 rating for each particular item
Echo "Rank Me: ";
Echo "<a href=".$_SERVER['PHP_SELF']."?mode=vote&voted=1&id=".$ratings[id].">Vote 1</a> | ";
Echo "<a href=".$_SERVER['PHP_SELF']."?mode=vote&voted=2&id=".$ratings[id].">Vote 2</a> | ";
Echo "<a href=".$_SERVER['PHP_SELF']."?mode=vote&voted=3&id=".$ratings[id].">Vote 3</a> | ";
Echo "<a href=".$_SERVER['PHP_SELF']."?mode=vote&voted=4&id=".$ratings[id].">Vote 4</a> | ";
Echo "<a href=".$_SERVER['PHP_SELF']."?mode=vote&voted=5&id=".$ratings[id].">Vote 5</a><p>";
}
?>
答案 0 :(得分:2)
您需要确保不使用0进行除法。如果从MySQL获得total
和votes
的值为0,则应绕过除法并设置固定值。
//This calculates the sites ranking and then outputs it - rounded to 1 decimal
if($ratings['total'] > 0 && $ratings['votes'] > 0) {
$current = $ratings['total'] / $ratings['votes'];
}
else{
$current = 0;
}
<强> P.S。强>
请注意我是如何引用$ratings
数组中的元素的。你应该总是这样做。
// This is INCORRECT. Causes error notices if you have error reporting on.
// and can have other consequences if you happen to use a `total` constant.
$ratings[total];
// It should be
$ratings['total']
答案 1 :(得分:2)
问题出在这里
$current = $ratings[total] / $ratings[votes];
如果没有投票,则将数字除以零。这很糟糕:))
添加一些验证,即$ ratings [vote]已设置且不为0.