Query to group by the contents of the field - php

Question

I need help to make query to group by content of field. I have the following Database:
+----+--------------+-----------------+------------------------------+
| id | depart_kode | depart_task | value |
+----+--------------+-----------------+------------------------------+
| 1 | 001 | Create Profil | Some Value |
| 2 | 001.12 | Create Profil | Some Value |
| 3 | 001.452 | Create Profil | Some Value |
| 4 | 002.914 | Create Profil | Some Value |
| 5 | 002 | Create Profil | Some Value |
| 6 | 003 | Create Profil | Some Value |
+----+--------------+-----------------+------------------------------+
I need to make a query where I group by depart_kode and I should print by the first 3 digits like this in format json
"001":[
{
"depart_kode":"001,
and other
},
{
"depart_kode":"001.12"
},
],
"002":[
{
"depart_kode":"002"
}
]
something like that, most importantly they will be grouped in an array based on the first 3 numbers like 001.
and json just an example, which I want to split into an array based on the first 3 digits

Answer 1

Something like this?
$departs = [];
foreach ($sqlRows as $row) {
$departKey = substr($row['depart_kode'], 0, 3);
if (!array_key_exists($departKey, $departs)) {
$departs[$departKey] = [];
}
$departs[$departKey][] = $row['depart_kode'];
}
Working example.
references
substr - get a specific part of a string (first 3 chars in our example)
array_key_exists - checks if the key in an array exists