Normalize/Transpose data from query with GROUP_CONCAT - php

Question

I'm stuck trying to create nested multiple object json arrays with group by
birth_place in my rest api app, this is my code in controller:
$db = db_connect();
$data = [
'status' => true,
'error' => null,
'data' => $db->query('SELECT birth_place, COUNT(id) as jumlah_data_user, GROUP_CONCAT(id) as id, GROUP_CONCAT(name) as name, GROUP_CONCAT(birth_date) as birth_date, GROUP_CONCAT(gender) as gender FROM users GROUP BY birth_place')->getResultArray()
];
return $this->respond($data, 200);
and this is my result, the data is successfully grouped but the combined data is not separated into multidimension arrays with create new title as users, but instead becomes a combined string.
"status": true,
"error": null,
"data": [
{
"birth_place": "Administrasi Jakarta Barat",
"jumlah_data_user": "3",
"id": "716,764,922",
"name": "Elvina Nuraini,Rina Kezia Novitasari,Viktor Firmansyah M.Pd",
"birth_date": "1975-08-28,1988-06-07,1989-05-13",
"gender": "female,female,male"
},
{
"birth_place": "Administrasi Jakarta Pusat",
"jumlah_data_user": "2",
"id": "993,866",
"name": "Mursinin Banawa Marbun M.Pd,Ibrahim Gunawan",
"birth_date": "1991-12-27,1995-01-01",
"gender": "male,male"
},
];
this result i was expecting when project running :
"status": true,
"error": null,
"data": [
{
"birth_place" : "Administrasi Jakarta Barat",
"jumlah_data_user" : 3,
"users": [
{
"id": 716,
"name": "Elvina Nuraini",
"birth_date": "1975-08-28",
"gender": "female"
},
{
"id": 764,
"name": "Rina Kezia Novitasari",
"birth_date": "1988-06-07",
"gender": "female"
},
{
"id": 922,
"name": "Viktor Firmansyah M.Pd",
"birth_date": "1989-05-13",
"gender": "male"
}
]
},
{
"birth_place": "Administrasi Jakarta Pusat",
"jumlah_data_user" : 2,
"users": [
{
"id": 993,
"name": "Mursinin Banawa Marbun M.Pd",
"birth_date": "1991-12-27",
"gender": "male"
},
{
"id": 866,
"name": "Ibrahim Gunawan",
"birth_date": "1995-01-01",
"gender": "male"
}
]
},
];
How to do that?

Answer 1

To restructured your grouped data, you need to iterate the rows then explode and transpose the last four columns containing delimited strings. (Demo)
$data = array_map(
fn($row) => [
'birth_place' => $row['birth_place'],
'jumlah_data_user' => $row['jumlah_data_user'],
'users' => array_map(
fn(...$col) => array_combine(['id', 'name', 'birth_date', 'gender'], $col),
explode(',', $row['id']),
explode(',', $row['name']),
explode(',', $row['birth_date']),
explode(',', $row['gender'])
)
],
$this->Users_model->getGroupedByBirthPlace();
);
That said, there is some important advice to offer:
In a MVC framework, we should not see database queries executed from the controller. The controller's job for this task is to collect data from the model (where a method there will collect database data) and then return the response payload.
Grouping and concatenating in the SQL is not advisable for this task.
There are data length limits to these concatenated strings,
when values contain commas, then there is a delimiter conflict, and
you are unnecessarily increasing the workload for the database.
It would make your model method more re-reusable if you made the result set less niched. A good model has methods that can be used more than once throughout the project.
Try not to mix English with Malay (or other non-English languages). The project will be easier to manage and review if the language is consistent. I'll suggest group_total instead of jumlah_data_user.
With a simpler payload coming from your model's query, there is no need to make iterated explode&transpose processes. This is the more professional way to design your application. (Demo)
$grouped = array_values(
array_reduce(
$this->Users_model->get(), // call the method whatever you like
function($data, $row) {
$group = $row['birth_place'];
$data[$group] ??= [
'birth_place' => $row['birth_place'],
'group_total' => 0
];
++$data[$group]['group_total'];
unset($row['birth_place']);
$data[$group]['users'][] = $row;
return $data;
}
)
);