<?php
$source = '
[
{
"PRODUCT" : "BANANA",
"BUY_PERIOD" : "202101",
"SALES_PERIOD" : "202101",
"PERCENT_OF_SALES" : "20"
},
{
"PRODUCT" : "BANANA",
"BUY_PERIOD" : "202101",
"SALES_PERIOD" : "202102",
"PERCENT_OF_SALES" : "10"
},
{
"PRODUCT" : "BANANA",
"BUY_PERIOD" : "202101",
"SALES_PERIOD" : "202103",
"PERCENT_OF_SALES" : "15"
},
{
"PRODUCT" : "BANANA",
"BUY_PERIOD" : "202101",
"SALES_PERIOD" : "202104",
"PERCENT_OF_SALES" : "35"
}
]
';
$data = json_decode($source, true);
$result = array_reduce(
$data,
function($res, $el) {
if (isset($res[$el['PRODUCT'] . "-" . $el['BUY_PERIOD']])) {
$res[$el['PRODUCT'] . "-" . $el['BUY_PERIOD']]['SALES_PERIOD'][$el['SALES_PERIOD']] = $el['PERCENT_OF_SALES'];
} else {
$res[$el['PRODUCT'] . "-" . $el['BUY_PERIOD']] = [
'PRODUCT' => $el['PRODUCT'],
'BUY_PERIOD' => $el['BUY_PERIOD'],
'SALES_PERIOD' => [
$el['SALES_PERIOD'] => $el['PERCENT_OF_SALES']
]
];
}
return $res;
},
$res
);
var_export(array_values($result));