PHP array sort by value and date (2 columns)

Question

I have multidimensional array in PHP. Something like

$mylist = array(
    array('ID' => 1, 'title' => 'Hello', 'datetime' => '2014-05-05 12:08 PM'),
    array('ID' => 2, 'title' => 'Amazing Pic', 'datetime' => '2014-05-06 11:08 PM'),
    array('ID' => 3, 'title' => 'Style', 'datetime' => '2014-05-02 9:08 PM'),
    array('ID' => 4, 'title' => 'Hello World', 'datetime' => '2014-05-01 5:08 PM')
);

My question is how do I sort by title and datetime? I spent quite some time searching on this. But I just found sort by two columns but with the same data type. I am now struggling to do this because I believe mine involve strtotime() function as this involves time.

This is what I have at this moment

function querySort ($x, $y) {
    return strcasecmp($x['title'], $y['title']);
}

function cmp($a, $b){
    $ad = strtotime($a['datetime']);
    $bd = strtotime($b['datetime']);
    return ($ad-$bd);
}

usort($mylist , 'querySort');

usort($mylist , 'cmp');

Could anyone help me on how to achieve this?

Another thing: It is not possible to sort by two parameter. If you sort by title and then by datetime, the result wont be different from a sort with only datetime. — Realitätsverlust, Jun 11 '14 at 05:11
@MarkGabriel I have tried using `array_multisort()` but ended up with only title is sorted correctly but not the date time — UserProg, Jun 11 '14 at 05:12
I found some solutions even in SO itself, it is possible to sort by more than one parameters. it is just that my parameter involves date time format, so this is little bit tricky for me. — UserProg, Jun 11 '14 at 05:14
Well according to this code, your array is sorted according to the title and then, you sort it according to the datetime. So the first sorting is useless. The output you get is an array which is sorted according to the datetime. — A.M.N.Bandara, Jun 11 '14 at 05:15
@Xl-lord that's correct. It is useless. So I am looking if I can sort by both columns. — UserProg, Jun 11 '14 at 05:15

score 0 · Answer 1 · answered Jun 11 '14 at 05:15

0

It looks like you need array_multisort. You can visit following link for more information http://www.php.net//manual/en/function.array-multisort.php

The basic idea would be cleared from example#2 on above link.

answered Jun 11 '14 at 05:15

Rohit Jangid

1,077
1
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19

score 0 · Accepted Answer · answered Jun 11 '14 at 05:17

The second usort overrides the output of the first usort.

What you need to do is merge the 2 sorting functions to order themselves by title and then date time.

Pseudocode would be :

function SortByTitleAndDateTime($a,$b)
    1) SortByTitle and return the value if it is non zero.
    2) If SortByTitle is zero (meaning the 2 values are the same in terms of title), 
        do SortByDateTime

In the end, you'd only need to call usort(array, SortByTitleAndDateTime).

score 0 · Answer 3 · answered Jun 11 '14 at 05:31

Try this,

$mylist = array(
    array('ID' => 1, 'title' => 'Hello', 'datetime' => '2014-05-05 12:08 PM'),
    array('ID' => 2, 'title' => 'Amazing Pic', 'datetime' => '2014-05-06 11:08 PM'),
    array('ID' => 3, 'title' => 'Style', 'datetime' => '2014-05-02 9:08 PM'),
    array('ID' => 4, 'title' => 'Hello World', 'datetime' => '2014-05-01 5:08 PM'),
     array('ID' => 5, 'title' => 'Boy', 'datetime' => '2014-05-01 5:08 PM')
);


// Obtain a list of columns
foreach ($mylist as $key => $row) {
    $dTime[$key]  = $row['datetime'];
    $title[$key] = $row['title'];
}

// Sort the data with dTimedescending, titleascending
// Add $mylist as the last parameter, to sort by the common key
array_multisort($dTime, SORT_DESC, $title, SORT_ASC, $mylist);

Your output will be

Array
(
    [0] => Array
        (
            [ID] => 2
            [title] => Amazing Pic
            [datetime] => 2014-05-06 11:08 PM
        )

    [1] => Array
        (
            [ID] => 1
            [title] => Hello
            [datetime] => 2014-05-05 12:08 PM
        )

    [2] => Array
        (
            [ID] => 3
            [title] => Style
            [datetime] => 2014-05-02 9:08 PM
        )

    [3] => Array
        (
            [ID] => 5
            [title] => Boy
            [datetime] => 2014-05-01 5:08 PM
        )

    [4] => Array
        (
            [ID] => 4
            [title] => Hello World
            [datetime] => 2014-05-01 5:08 PM
        )

)

I have added ID no 5 for demonstration, so that date wise sorted in descending order and title wise sorted in ascending order

score 0 · Answer 4 · answered Jun 11 '14 at 05:36

I ended up with something like Mark Gabriel's logic. This will sort out the title first, and followed by the date time. So here it is:

function SortByTitleAndDateTime($a,$b){
    if ( strcasecmp($a['title'], $b['title']) != 0 ){
        return strcasecmp($a['title'], $b['title']);
    }
    else{
        $ad = strtotime($a['datetime']);
        $bd = strtotime($b['datetime']);
        return ($ad-$bd);
    }
}
usort($mylist, 'SortByTitleAndDateTime');

Hope this helps other people as well.

PHP array sort by value and date (2 columns)

4 Answers4

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