Array for subseries on highcharts Drilldown - php

Question

I'm having some problems generating graphs with drilldown in Highcharts.
I'm using Highcharts to render a pie with drilldown series.
I need to transform this output json
Drilldownseries = [
{
"name": "LAZIO",
"data": [["ROMA", 28]],
"id": "LAZIO"
},
{
"name": "LAZIO",
"data": [["FROSINONE", 218]],
"id": "LAZIO"
},
{
"name": "LAZIO",
"data": [["LATINA", 212]],
"id": "LAZIO"
},
{
"name": "TOSCANA",
"data": [["FIRENZE", 2]],
"id": "TOSCANA"
},
{
"name": "TOSCANA",
"data": [["LIVORNO", 5]],
"id": "TOSCANA"
},
{
"name": "TOSCANA",
"data": [["PISA", 9]],
"id": "TOSCANA"
}
];
to
Drilldownseries = [
{
"name": "LAZIO",
"data": [["ROMA", 28], ["FROSINONE", 218], ["LATINA", 212]],
"id": "LAZIO"
},
{
"name": "TOSCANA",
"data": [["FIRENZE", 2], ["LIVORNO", 5], ["PISA", 9]],
"id": "TOSCANA"
}
];
This is the part of query that populates the array:
...
if($res3)
{
$i = 0;
while ($row = mysqli_fetch_array($res3, MYSQLI_ASSOC))
{
$row3[$i]["name"] = $row["name"];
$row3[$i]["data"] = [[$row["subname"],$row["data"]]];
$row3[$i]["id"] = $row["id"];
$i++;
};
$row3 = json_encode($row3,JSON_NUMERIC_CHECK);
};
I'd prefer to extract the array with php well formed, but should be the same tranform the json.
PHP 7.2
Highcharts 6.1.1

Answer 1

for benefit of all, this is my solution. Code refined should be appreciated :)
First removed square brackets in code below
$row3[$i]["data"] = [$row["subname"],$row["data"]];
then create the new array so
$repl = array();
$i = 0;
foreach ($row3 as $value) {
if (!isset($repl[$i]['id'])) {
$repl[$i]['id'] = $value['id'];
$repl[$i]['name'] = $value['name'];
$repl[$i]['data'] = [$value['data']];
} elseif (($repl[$i]['id']) <>$value['id']) {
$i++;
$repl[$i]['id'] = $value['id'];
$repl[$i]['name'] = $value['name'];
$repl[$i]['data'] = [$value['data']];
} else {
array_push($repl[$i]['data'], $value['data']);
}
}
$resultx = json_encode($repl,JSON_NUMERIC_CHECK);
thanks