Get max value in php from multiple json data

Question

Currently I have this json data

1st Data

{
    "id": 41,
    "userId": 9,
    "description": null,
    "updated_by": "Juan Dela Cruz",
    "created_at": "2019-09-18 10:07:34",
    "updated_at": "2019-09-18 10:07:34"
}

2nd Data

{
    "id": 2,
    "userId": 9,
    "description": null,
    "updated_by": null,
    "created_at": "2019-09-16 12:46:56",
    "updated_at": "2019-09-16 12:46:56"
}

I have this variable $myData if you try to echo this $myData the above json will be the expected output.

Is it possible to get the most recent created_at using this max() function of php?

My expected output would be

1st Data

{
    "id": 41,
    "userId": 9,
    "description": null,
    "updated_by": "Juan Dela Cruz",
    "created_at": "2019-09-18 10:07:34",
    "updated_at": "2019-09-18 10:07:34"
}

Since the created_at is recently created than to the 2nd data.

if is it possible you can just do order by from db if you are fetching it from your own local db — Jaymin, Sep 18 '19 at 05:57
Unfortunately can't do that in my situation.. Of course in my db I can simply query something like this `ORDER BY created_at DESC LIMIT 1` but in my php query I can't simply do this. — Pablo, Sep 18 '19 at 05:57
If you know how to decode the data - https://stackoverflow.com/questions/2910611/php-sort-a-multidimensional-array-by-element-containing-date gives all you need. — Nigel Ren, Sep 18 '19 at 06:27

score 0 · Answer 1 · answered Sep 18 '19 at 06:09

0

Try

SELECT * FROM tbl WHERE 1 = 1 ORDER BY created_at DESC LIMIT 1,1; OR SELECT * FROM tbl ORDER BY created_at DESC LIMIT 1,1;

answered Sep 18 '19 at 06:09

Mudasir Syed

121
7

score 0 · Answer 2 · answered Sep 18 '19 at 06:12

Make one array of two json data and keep key as after converting created_at using strtotime(). Then use max() in all array_keys() and print the array.

$a = '{"id":41,"userId":9,"description":null,"updated_by":"Juan Dela Cruz","created_at":"2019-09-18 10:07:34","updated_at":"2019-09-18 10:07:34"}';
$b = '{"id":2,"userId":9,"description":null,"updated_by":null,"created_at":"2019-09-16 12:46:56","updated_at":"2019-09-16 12:46:56"}';
$arr1 = json_decode($a, true);
$key1 = strtotime($arr1['created_at']);
$arr[$key1] = $arr1;
$arr2 = json_decode($b, true);
$key2 = strtotime($arr2['created_at']);
$arr[$key2] = $arr2;
//print_r($arr);
$key = max(array_keys($arr));
print_r($arr[$key]);

Demo

score 0 · Answer 3 · answered Sep 18 '19 at 06:19

This is how you can achieve it using usort function.

<?php
// $json = "{"id":41,"userId":9,"description":null,"updated_by":"Juan Dela Cruz","created_at":"2019-09-18 10:07:34","updated_at":"2019-09-18 10:07:34"}";
$arr[] = array('id' => 41, "userId" => 9,"created_at" => "2019-09-18 10:07:34");
$arr[] = array('id' => 42, "userId" => 10,"created_at" => "2019-09-16 12:46:56");
echo '<pre>';
print_r($arr);
usort($arr, function($a, $b) {
  $ad = new DateTime($a['created_at']);
  $bd = new DateTime($b['created_at']);

  if ($ad == $bd) {
    return 0;
  }

  return $ad < $bd ? -1 : 1;
});
echo '<pre>';
print_r($arr);

?>

I am supposing that my $arr is it in this format.

Array
(
    [0] => Array
        (
            [id] => 41
            [userId] => 9
            [created_at] => 2019-09-18 10:07:34
        )

    [1] => Array
        (
            [id] => 42
            [userId] => 10
            [created_at] => 2019-09-16 12:46:56
        )

)

After Sorting, your array will be like this:

Array
(

        [0] => Array
            (
                [id] => 42
                [userId] => 10
                [created_at] => 2019-09-16 12:46:56
            )

        [1] => Array
            (
                [id] => 41
                [userId] => 9
                [created_at] => 2019-09-18 10:07:34
            )

    )

MjM · Answer 4 · 2019-09-18T06:53:15.243

<?php
$json = '{
"0":{
    "id": 41,
    "userId": 9,
    "description": null,
    "updated_by": "Juan Dela Cruz",
    "created_at": "2019-09-18 10:07:34",
    "updated_at": "2019-09-18 10:07:34"
},
"1":{
    "id": 2,
    "userId": 9,
    "description": null,
    "updated_by": null,
    "created_at": "2019-09-16 12:46:56",
    "updated_at": "2019-09-16 12:46:56"
}

}';
$jsonDecoded = json_decode($json, true);

function array_sort_by_column(&$arr, $col, $dir = SORT_DESC) {
    $sort_col = array();
    foreach ($arr as $key=> $row) {
        $sort_col[$key] = $row[$col];
    }

    array_multisort($sort_col, $dir, $arr);
}


array_sort_by_column($jsonDecoded, 'created_at');

print_r($jsonDecoded);
?>

Output Will be:

Array
(
    [0] => Array
        (
            [id] => 41
            [userId] => 9
            [description] => 
            [updated_by] => Juan Dela Cruz
            [created_at] => 2019-09-18 10:07:34
            [updated_at] => 2019-09-18 10:07:34
        )

    [1] => Array
        (
            [id] => 2
            [userId] => 9
            [description] => 
            [updated_by] => 
            [created_at] => 2019-09-16 12:46:56
            [updated_at] => 2019-09-16 12:46:56
        )

)

If you want to change the sorting order then change the parameter $dir to $dir = SORT_ASC, that is : function array_sort_by_column(&$arr, $col, $dir = SORT_ASC)

Then, To get the recent created_at from the array you can add the following code (If the sort order is SORT_DESC then use min() else use max() ):

print_r($jsonDecoded[min(array_keys($jsonDecoded))]);

Get max value in php from multiple json data

4 Answers4