Sorting array on two conditions

Question

Ok, so I am having trouble coming up with a solution to my problem. Basically, what I am trying to accomplish is to total the number of registrations in the last twelve months, starting with the current month.

First, since I cannot guarantee that each month would have a return, I built an array and populated it with my query results. I was able to pull all the data that I needed, but I am having trouble "sorting" them as you will.

I want to be able to display it in this manner, ex:

It is currently october so the months would list like this:

Nov 2014, Dec 2014, Jan 2015, Feb 2015, March 2015, ... October 2015.

Using this array

$months = array(
            '1'=>array('TOTAL'=>0, 'YEAR'=>NULL), 
            '2'=>array('TOTAL'=>0, 'YEAR'=>NULL), 
            '3'=>array('TOTAL'=>0, 'YEAR'=>NULL), 
            '4'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '5'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '6'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '7'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '8'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '9'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '10'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '11'=>array('TOTAL'=>0, 'YEAR'=>NULL),  
            '12'=>array('TOTAL'=>0, 'YEAR'=>NULL)
        );

And populating it with the results I get:

key: 1 (January) total: 17 year: 2015
key: 2 (February) total: 20 year: 2015
key: 3 (March) total: 23 year: 2015
key: 4 (April) total: 29 year: 2015
key: 5 (May) total: 26 year: 2015
key: 6 (June) total: 26 year: 2015
key: 7 (July) total: 26 year: 2015
key: 8 (August) total: 24 year: 2015
key: 9 (September) total: 22 year: 2015
key: 10 (October) total: 24 year: 2015
key: 11 (November) total: 30 year: 2014
key: 12 (December) total: 42 year: 2014

Here's the query/loop

    $query = "SELECT MONTH(DATE_ADDED) as MONTH_NUMBER, MONTHNAME(DATE_ADDED) as MONTH_NAME, COUNT(*) as TOTAL_REGISTRATIONS, YEAR(DATE_ADDED) AS YEAR FROM MEMBERS WHERE DATE_ADDED >= (CURDATE() - INTERVAL (DAY(CURDATE()) - 1) DAY) - INTERVAL 11 MONTH GROUP BY MONTH(DATE_ADDED) ORDER BY DATE_ADDED ASC";
    $result = mysql_query($query) or die(mysql_error());

while($row = mysql_fetch_assoc($result)){

    $months[$row['MONTH_NUMBER']]['NAME'] = $row['MONTH_NAME'];
    $months[$row['MONTH_NUMBER']]['TOTAL'] = $row['TOTAL_REGISTRATIONS'];
    $months[$row['MONTH_NUMBER']]['YEAR'] = $row['YEAR'];
    $months[$row['MONTH_NUMBER']]['MONTH_NUM'] = $row['MONTH_NUMBER'];

}

    foreach($months as $key=>$data){
        echo 'key: '.$key. ' ('.$data['NAME'].')   total:   '.$data['TOTAL'].'      year: '.$data['YEAR'].'<br/>';
    }
    exit;

Edit: So far, I've been able to accomplish this:

key: 12 (December) total: 42 year: 2014
key: 11 (November) total: 30 year: 2014
key: 10 (October) total: 24 year: 2015
key: 9 (September) total: 22 year: 2015
key: 8 (August) total: 24 year: 2015
key: 7 (July) total: 26 year: 2015
key: 6 (June) total: 26 year: 2015
key: 5 (May) total: 26 year: 2015
key: 4 (April) total: 29 year: 2015
key: 3 (March) total: 23 year: 2015
key: 2 (February) total: 20 year: 2015
key: 1 (January) total: 17 year: 2015

using this code:

function sortArray(array $a, array $b) {

    if($a['YEAR'] <= $b['YEAR'] && $a['MONTH_NUM'] < $b['MONTH_NUM']){
        return 1;
    }elseif($a['YEAR'] <= $b['YEAR'] && $a['MONTH_NUM'] > $b['MONTH_NUM']){
        return -1;
    }elseif($a['YEAR'] >= $b['YEAR'] && $a['MONTH_NUM'] > $b['MONTH_NUM']){
        return -1;
    }elseif($a['YEAR'] >= $b['YEAR'] && $a['MONTH_NUM'] < $b['MONTH_NUM']){
        return 1;
    } else {
        return 0;
    }

}
// Sort
uasort($months, 'sortArray');

Edit: You can see it sorts by the year properly, but lists the months the wrong way.

Edit: Desired Output

key: 11 (November) total: 00 year: 2014
key: 12 (December) total: 00 year: 2014
key: 1 (January) total: 00 year: 2015
key: 2 (February) total: 00 year: 2015
key: 3 (March) total: 00 year: 2015
key: 4 (April) total: 00 year: 2015
key: 5 (May) total: 00 year: 2015
key: 6 (June) total: 00 year: 2015
key: 7 (July) total: 00 year: 2015
key: 8 (August) total: 00 year: 2015
key: 9 (September) total: 00 year: 2015
key: 10 (October) total: 00 year: 2015

---

Ultimately, I will be displaying these in a bar graph showing the total per month over the last year.

I don't know if this is the best way to go about doing this, any suggestions are welcome.

Answer 1

I think your answer lies as an user contribution note on PHP Docs's uasort() function page, by "clement.hk". I've adapted it to your problem and it seems to work!

<?php

// array reproduction
$months = array(
        '1'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '2'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '3'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '4'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '5'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '6'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '7'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '8'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '9'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '10'=>array('TOTAL'=>0, 'YEAR'=>2015),
        '11'=>array('TOTAL'=>0, 'YEAR'=>2014),
        '12'=>array('TOTAL'=>0, 'YEAR'=>2014)
);

// "clement.hk"'s alternate version of "uasort", where it keeps
// the index order when $a == $b. Credits to him!
function stable_uasort(&$array, $cmp_function) {
    if(count($array) < 2) {
        return;
    }
    $halfway = count($array) / 2;
    $array1 = array_slice($array, 0, $halfway, TRUE);
    $array2 = array_slice($array, $halfway, NULL, TRUE);

    stable_uasort($array1, $cmp_function);
    stable_uasort($array2, $cmp_function);
    if(call_user_func($cmp_function, end($array1), reset($array2)) < 1) {
        $array = $array1 + $array2;
        return;
    }
    $array = array();
    reset($array1);
    reset($array2);
    while(current($array1) && current($array2)) {
        if(call_user_func($cmp_function, current($array1), current($array2)) < 1) {
            $array[key($array1)] = current($array1);
            next($array1);
        } else {
            $array[key($array2)] = current($array2);
            next($array2);
        }
    }
    while(current($array1)) {
        $array[key($array1)] = current($array1);
        next($array1);
    }
    while(current($array2)) {
        $array[key($array2)] = current($array2);
        next($array2);
    }
    return;
}

// the equal comparison is pointless since you have twelve months of the same
// year... we need comparison only when it differs
stable_uasort($months, function ($a, $b) {
/*     if($a['YEAR'] == $b['YEAR']) {
        return 0;
    } */
    return ($a['YEAR'] > $b['YEAR']) ? 1 : -1;
});


echo '<pre>';
print_r($months);

The output:

Array
(
    [11] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2014
        )

    [12] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2014
        )

    [1] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [2] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [3] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [4] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [5] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [6] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [7] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [8] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [9] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

    [10] => Array
        (
            [TOTAL] => 0
            [YEAR] => 2015
        )

)

Seems uasort can go unstable when issuing multi-leveled sortings while it maintains array index order when they have same values. The talking is that is currently fixed on PHP7 for small size arrays (<16), so if you dare it, may be worth the trying!