convert some value from mysql query using php - php

Question

using php I make a query to mysql. Inside my query, some values are in seconds (just some of them), I'd like to convert them into mm:ss. So I need to move into my "array" query and I do not understand how to move inside my query result, attribute after attribute.
Here is my db :
In my php code, I make the query and then for each row I put it inside an array.
$data=array();
$q=mysqli_query($mysqli, "SELECT * FROM TEST3612 WHERE user_id=$queryid");
while ($row=mysqli_fetch_object($q)) {
//$data[]=gmdate("H:i:s", $row%86400);
$data[]=$row;
}
I'd like then to move into my array, and when I have the attribute CS for example, convert the value.
Here is what I tried :
foreach($data as $value) {
if ($value['CS']) {
$value['CS'] = gmdate("H:i:s", $value%86400);
}
}
I got an error. I don't know how to move into my array, a select a element of a object. I thought I did it good but apparently no.
Thank you for you help.

Answer 1

mysqli_fetch_object returns objects, not arrays. Also you used $value instead of $value->CS inside of gmdate. So you should iterate like this:
foreach($data as $value) {
if ($value->CS) {
$value->CS = gmdate("H:i:s", $value->CS % 86400);
}
}
Alternativly you can write this directly in your while loop, so you don't need the foreach loop. I would say this is the better solutions because you don't write unnecessary code and performance gets improved a little bit:
while ($row = mysqli_fetch_object($q)) {
if ($row->CS) {
$row->CS = gmdate("H:i:s", $row->CS % 86400);
}
$data[] = $row;
}