Using Median Function with sort and Array - php

Question

I am trying to calculate the Median of an array. I was able to get the MIN, MAX, AVG, But I am having difficulty with the Median and the way the display sorts the information.
My Question is How do I get the Median, using a function individually for each status. (Status being A, C, E, L, P, W)
My Code is:
<?php
echo "<p><b>A</b> = Active, <b>E</b> = Expired, <b>L</b> = Canceled, <b>P</b> = Pending, <b>W</b> = Withdrawn</p>\n";
// COUNT STATUS
include '_inc/include.php';
$query = "SELECT status, COUNT(status) FROM median GROUP BY status";
$result = mysql_query($query) or die(mysql_error());
// Print out result
while($row = mysql_fetch_array($result)){
echo "There are ". $row['COUNT(status)'] ." ". $row['status'] ." items.";
echo "<br />";
}
?>
The display is:
A = Active, C = Closed, E = Expired, L = Canceled, P = Pending, W = Withdrawn
There are 6 A items
There are 2 C items
There are 9 E items
There are 4 L items
There are 2 P items
My Code is:
$query = "SELECT listprice, status, MIN(listprice), COUNT(status) FROM median GROUP BY status";
$result = mysql_query($query) or die(mysql_error());
// Print out result
while($row = mysql_fetch_array($result)){
echo "The MIN list price for the ". $row['COUNT(status)'] ." ". $row['status'] ." is $" . $row['MIN(listprice)'];
echo "<br />";
}
?>
The display is:
The MIN list price for the 6 A is $139900.00
The MIN list price for the 2 C is $149900.00
The MIN list price for the 9 E is $138000.00
The MIN list price for the 4 L is $229000.00
The MIN list price for the 2 P is $179000.00
The MAX and AVG is similar to the above.
I tried to include a function to calculate the Median (MED)
<?php
function median($arr)
{
sort($arr);
$count = count($arr); //count the number of values in array
$middleval = floor(($count-1)/2); // find the middle value, or the lowest middle value
if ($count % 2) { // odd number, middle is the median
$median = $arr[$middleval];
} else { // even number, calculate avg of 2 medians
$low = $arr[$middleval];
$high = $arr[$middleval+1];
$median = (($low+$high)/2);
}
return $median;
}
echo median(array($lp)) . "\n"; // 153500
echo "<p> </p>";
echo median(array(4.1, 7.2, 1.7, 9.3, 4.4, 3.2)) . "\n"; // 4.25
?>
This works for a static array, but how do I calculate it to look like the above MIN, MAX?
<?php
$i=0;
while ($i < $num) {
$ld=mysql_result($result,$i,"listdate");
$cd=mysql_result($result,$i,"closedate");
$contractd=mysql_result($result,$i,"contractdate");
$s=mysql_result($result,$i,"status");
$scd=mysql_result($result,$i,"statuschangedate");
$wd=mysql_result($result,$i,"withdrawdate");
$cand=mysql_result($result,$i,"canceldate");
$lp=mysql_result($result,$i, "listprice");
$sp=mysql_result($result,$i,"soldprice");
$gla=mysql_result($result,$i,"gla");
$b=mysql_result($result,$i,"built");
$o=mysql_result($result,$i,"owner");
$fs=mysql_result($result,$i,"fore");
$ss=mysql_result($result,$i,"shortsale");
$f=mysql_result($result,$i,"features");
?>
I think maybe the reason I having so much trouble with this is that the data in the table is uploaded via file upload (csv). But I didn't think that really had anything to do with it because the data is already there.
I used $lp for listprice in place of the static array in the median function, that is were it goes blank.

Answer 1

...that is where it goes blank.
Blank pages are an indicator of an PHP error being thrown but having error display settings turned off. Make sure you turn on error reporting to see the issue.
One thing of importance, the deprecated mysql_result() function will retrieve the contents of one cell from a MySQL result set. If you were hoping to have multiple values by passing your median function array($lp) it's not going to happen that way. Additionally, if the mysql_result() function fails or doesn't find a result, it returns false mean the array you pass to your median function is now array(false).
Those are some things to keep in mind while troubleshooting. Turn on error reporting and the problem should be much easier to deduce.

Answer 2

There is no median function for most MySQL versions. However, MariaDB 10.3.3 just introduced a median function.