Question

I have this script:

<?php
$result = mysql_query("SELECT * FROM high ORDER BY KC DESC LIMIT 20");

while($row = mysql_fetch_array($result))
{
echo $row['KC'];
echo "<br />";
}
?>

And this

<?php
$result = mysql_query("SELECT * FROM high ORDER BY DC DESC LIMIT 20");

while($row = mysql_fetch_array($result))
{
echo $row['DC'];
echo "<br />";
}
?>

I want to divine DC and KC and want it to show the value after dividing.

For example DC = 80 and KC = 30

The system will divine KC to DC ( 80 / 30 = 2.666666666666667 )

I tried doing this:

<?php
$result = mysql_query("SELECT * FROM high ORDER BY Runecraftlvl DESC LIMIT 20");
while($row = mysql_fetch_array($result))
{
echo $row['kills'] / $row['deaths'];
echo "<br />";
}
?>

It works just fine, but if both variables KC and DC are 0, it gives me this error:

Warning: Division by zero in /home/justxpp1/public_html/high/highscores.php on line 86

Why is that happening?

http://gyazo.com/26b3309c8e72d89ccc4cd32f4cdae7cd

Answer 1

While this is a too basic question, here’s a possible solution. You only have to check the second variable, the first one is okay even if it’s 0:

<?php
$result = mysql_query("SELECT * FROM high ORDER BY Runecraftlvl DESC LIMIT 20");
while($row = mysql_fetch_array($result))
  {
  echo ($row['deaths'] != 0) ? $row['kills'] / $row['deaths'] : '-';
  echo "<br />";
  }
?>

PD, it uses the ternary operator.

I found a post where it explains how to do what you requested. For your particular request, this is also important: How to avoid the “divide by zero” error in SQL?