PHP re-group array by each column to multiple array without loop - php

Question

PHP re-group array by each column to multiple array without loop
In Laravel DB return, i.e. ->get()->toArray() result is as such:
[
['ts' => 1234, 'a' => 3, 'b' => 2],
['ts' => 1244, 'a' => 2, 'b' => 6],
['ts' => 1254, 'a' => 8, 'b' => 3],
]
Is there any way that I am able to transform the data to as such:
[
['column' => 'a', 'values' => [[1234, 3], [1244, 2], [1254, 8]],
['column' => 'b', 'values' => [[1234, 2], [1244, 6], [1254, 3]],
]
I just wish to know if there's any best / efficient way to render the transformation as described above. Avoid re looping again as data is already available, it can be thought as a data formatting question. Also, I do not wish to use additional array if possible.
Things that I've already looked includes ->get()->map(function()), however this is sequential and I am not able to get values in 2D array as a result.

Answer 1

You'll want to map over your items and return the ts value, as well as the value for each column, respectively:
$items = Model::all();
$result = [
[
'column' => 'a',
'values' => $items->map(function ($item) {
return [$item->ts, $item->a];
})
],
[
'column' => 'b',
'values' => $items->map(function ($item) {
return [$item->ts, $item->b];
})
],
];
If you want to combine the logic for both columns, create a collection of column names, and map over those:
$items = Model::all();
$result = collect(['a', 'b'])->map(function ($column) use ($items) {
$values = $items->map(function ($item) use ($column) {
return [$item->ts, $item->{$column}];
});
return compact('column', 'values');
});