how to create a pivot array in php - php

Question

I have the following :
$data = [
{model_num : "ABC", revision : "AA", "testRecipeID":85, value : 31.25, treatment : 'Pressure' },
{model_num : "ABC", revision : "AA", "testRecipeID":85, value : 31.25, treatment : 'Gas' },
{model_num : "ABC", revision : "AA", "testRecipeID":85, value : 33.12, treatment : 'Temp' },
{model_num : "ABC", revision : "AA", "testRecipeID":85, value : 25.87, treatment : 'Current' },
{model_num : "ABC", revision : "AB", "testRecipeID":86, value : 26.63, treatment : 'Pressure' },
{model_num : "ABC", revision : "AB", "testRecipeID":86, value : 26.00, treatment : 'Gas' },
{model_num : "ABC", revision : "AB", "testRecipeID":86, value : 23.75, treatment : 'Temp' }
];
and i would like to end up with something like this:
var data=[{model_num : "ABC", revision : "AA", "testRecipeID":85, "Pressure":31.25, "Gas":31.25, "Temp": 33.12,"Current":25.87 },{model_num : "ABC", revision : "AB", "testRecipeID":86, "Gas":26.00,"Temp":23.75}]
I know how to do this in JS but not on PHP and it turns out I need to do it in my php so that I can process the large amounts of data that I have. I have this based on another question that I found but It doesn't work it returns a 0
$table = array();
$round_names = array();
$total = array();
foreach ($data as $score)
{
$round_names[] = $score->treatment;
$table[$score->testRecipeID][$score->treatment] = $score->value;
$total[$score->testRecipeID] += $score->value;
print_r($round_names);
}
$round_names = array_unique($round_names);
foreach ($table as $player => $rounds)
{
echo "$player\t";
foreach ($round_names as $round)
echo "$rounds[$round]\t";
echo "$total[$player]\n";
}
any help will be greatly appreciated!
this is how i do it in JS
var result = [];
data.forEach(function(e) {
var a = e.model_num + '|' + e.revision+ '|'e.recipeID;
if(!this[a]) {
this[a] = {model_num: e.model_num, revision: e.revision, recipeID: e.recipeID}
result.push(this[a]);
}
this[a][e.treatment] = e.value;
}, {});

Answer 1

If you need the structure, you can try with JSON Encode:
<?php
$arr = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5);
echo json_encode($arr);
?>
Which outputs:
{"a":1,"b":2,"c":3,"d":4,"e":5}
If you need it to be an array, use:
echo json_encode(array($arr));

Answer 2

This is your JS function in PHP
<?php
$data = '[
{"model_num" : "ABC", "revision" : "AA", "testRecipeID":85, "value" : 31.25, "treatment" : "Pressure" },
{"model_num" : "ABC", "revision" : "AA", "testRecipeID":85, "value" : 31.25, "treatment" : "Gas" },
{"model_num" : "ABC", "revision" : "AA", "testRecipeID":85, "value" : 33.12, "treatment" : "Temp" },
{"model_num" : "ABC", "revision" : "AA", "testRecipeID":85, "value" : 25.87, "treatment" : "Current" },
{"model_num" : "ABC", "revision" : "AB", "testRecipeID":86, "value" : 26.63, "treatment" : "Pressure" },
{"model_num" : "ABC", "revision" : "AB", "testRecipeID":86, "value" : 26.00, "treatment" : "Gas" },
{"model_num" : "ABC", "revision" : "AB", "testRecipeID":86, "value" : 23.75, "treatment" : "Temp" }
]';
$data = json_decode($data);
$result = [];
foreach ($data as $row) {
$a = $row->model_num . '|' . $row->revision . '|' . $row->testRecipeID;
if (! array_key_exists($a, $result)) {
$result[$a] = [
'model_num' => $row->model_num,
'revision' => $row->revision,
'testRecipeID' => $row->testRecipeID
];
}
}

Answer 3

Because neither of the previous answers managed to provide the desired output, I am compelled to answer this pivot question.
Create a temporary string from the 3 identifying column values.
Use that string as the first level key while grouping related row data.
The null coalescing assignment operator spares you needing to call isset() to check if the group has been encountered before. If it is the first encounter, save the three core elements to the row.
Unconditionally push the dynamically keyed value into the group's row.
5 When finished iterating clear away the temporary keys with array_values().
Code: (Demo)
$data = [
['model_num' => 'ABC', 'revision' => 'AA', 'testRecipeID' => 85, 'value' => 31.25, 'treatment' => 'Pressure'],
['model_num' => 'ABC', 'revision' => 'AA', 'testRecipeID' => 85, 'value' => 31.25, 'treatment' => 'Gas'],
['model_num' => 'ABC', 'revision' => 'AA', 'testRecipeID' => 85, 'value' => 33.12, 'treatment' => 'Temp'],
['model_num' => 'ABC', 'revision' => 'AA', 'testRecipeID' => 85, 'value' => 25.87, 'treatment' => 'Current'],
['model_num' => 'ABC', 'revision' => 'AB', 'testRecipeID' => 86, 'value' => 26.63, 'treatment' => 'Pressure'],
['model_num' => 'ABC', 'revision' => 'AB', 'testRecipeID' => 86, 'value' => 26.0, 'treatment' => 'Gas'],
['model_num' => 'ABC', 'revision' => 'AB', 'testRecipeID' => 86, 'value' => 23.75, 'treatment' => 'Temp']
];
$result = [];
foreach ($data as $row) {
$compositeKey = "{$row['model_num']}-{$row['revision']}-{$row['testRecipeID']}";
$result[$compositeKey] ??= [
'model_num' => $row['model_num'],
'revision' => $row['revision'],
'testRecipeID' => $row['testRecipeID']
];
$result[$compositeKey][$row['treatment']] = $row['value'];
}
var_export(array_values($result));
Output:
array (
0 =>
array (
'model_num' => 'ABC',
'revision' => 'AA',
'testRecipeID' => 85,
'Pressure' => 31.25,
'Gas' => 31.25,
'Temp' => 33.12,
'Current' => 25.87,
),
1 =>
array (
'model_num' => 'ABC',
'revision' => 'AB',
'testRecipeID' => 86,
'Pressure' => 26.63,
'Gas' => 26.0,
'Temp' => 23.75,
),
)