How to merge identical array values, and place the different ones inside a sub-array

Question

I have the following problem.

I have an array returned from the database which is as follows:

array(4) {
[0]=>
  array(4) {
    ["groupoURL"]=> string(7) "express"
    ["grupoNome"]=> string(13) "Express"
    ["subgrupoURL"]=> string(4) "aves"
    ["subgrupoNome"]=> string(4) "Aves"
  }
[1]=>
  array(4) {
    ["groupoURL"]=> string(7) "express"
    ["grupoNome"]=> string(13) "Express"
    ["subgrupoURL"]=> string(4) "peixes"
    ["subgrupoNome"]=> string(4) "Peixes"
  }
[2]=>
  array(4) {
    ["groupoURL"]=> string(7) "executivo"
    ["grupoNome"]=> string(13) "Executivo"
    ["subgrupoURL"]=> string(4) "aves"
    ["subgrupoNome"]=> string(4) "Aves"
  }
[3]=>
  array(4) {
    ["groupoURL"]=> string(7) "executivo"
    ["grupoNome"]=> string(13) "Executivo"
    ["subgrupoURL"]=> string(4) "carnes"
    ["subgrupoNome"]=> string(4) "Carnes"
  }
}

I am trying to merge the values that are identical (In this case, it will always be the keys "groupURL" and "groupName", and the remaining "subgroupURL" and "subgroupName" should become an array and their values be joined.

My end result would need to stay this way:

array(2) {
[0]=>
  array(3) {
    ["groupoURL"]=> string(7) "express"
    ["grupoNome"]=> string(13) "Express"
    ["subgrupos"]=> array(
        array(
            ["subgrupoURL"]=> "aves",
            ["subgrupoNome"]=> "Aves"
        ),
        array(
            ["subgrupoURL"]=> "peixes",
            ["subgrupoNome"]=> "Peixes"
        ),
    )
  }
[1]=>
  array(3) {
    ["groupoURL"]=> string(7) "executivo"
    ["grupoNome"]=> string(13) "Executivo"
    ["subgrupos"]=> array(
        array(
            ["subgrupoURL"]=> "aves",
            ["subgrupoNome"]=> "Aves"
        ),
        array(
            ["subgrupoURL"]=> "carnes",
            ["subgrupoNome"]=> "Carnes"
        ),
    )
  }
}

I don’t have a solution yet, but I’m trying to create something, but this wouldn’t be the ideal way:

    $test = ...Recebe os resultados da consulta
    $newArray = [];
    foreach($test as $array) {
        switch ($array["groupoURL"]) {
            case "express":
                 $newArray["express"]["grupoNome"] = $array["grupoNome"];
                 $newArray["express"]["grupoURL"] = $array["groupoURL"];
                 $newArray["express"]["subgrupos"][] = ["subgrupoNome" => $array["subgrupoNome"], "subgrupoURL" => $array["subgrupoURL"]];
                 break;
            case "executivo":
                 $newArray["executivo"]["grupoNome"] = $array["grupoNome"];
                 $newArray["executivo"]["grupoURL"] = $array["groupoURL"];
                 $newArray["executivo"]["subgrupos"][] = ["subgrupoNome" => $array["subgrupoNome"], "subgrupoURL" => $array["subgrupoURL"]];
                 break;
            ...
            default: 
                break;
        }
    }

The above solution works, but I am checking the "group" of each item. It may happen that the name of this group is changed, or a new group is inserted.

Would anyone have any suggestions? Thank you for your attention.

Answer 1

In hand:

<?php

$resultSet = [
    [
        'grupoURL'     => 'express',
        'grupoNome'    => 'Express',
        'subgrupoURL'  => 'aves',
        'subgrupoNome' => 'Aves'
    ],
    [
         'grupoURL'     => 'express',
         'grupoNome'    => 'Express',
         'subgrupoURL'  => 'peixes',
         'subgrupoNome' => 'Peixes'
    ],
    [
         'grupoURL'     => 'executivo',
         'grupoNome'    => 'Executivo',
         'subgrupoURL'  => 'aves',
         'subgrupoNome' => 'Aves'
    ],
    [
         'grupoURL'     => 'executivo',
         'grupoNome'    => 'Executivo',
         'subgrupoURL'  => 'carnes',
         'subgrupoNome' => 'Carnes'
    ]
];

$arrayFinal = [];

for ($i=0; $i<count($resultSet); $i++) {
    $inserido = false;
    for ($j=0; $j<count($arrayFinal); $j++) {
        if ($arrayFinal[$j]['grupoURL'] == $resultSet[$i]['grupoURL'] && $arrayFinal[$j]['grupoNome'] == $resultSet[$i]['grupoNome']) {
            $inserido = true;
            $arrayFinal[$j]['subgrupos'][] = [
                'subgrupoURL'  => $resultSet[$i]['subgrupoURL'],
                'subgrupoNome' => $resultSet[$i]['subgrupoNome']
            ];
        }
    }
    if (!$inserido) {
        $arrayFinal[] = [
            'grupoURL'  => $resultSet[$i]['grupoURL'],
            'grupoNome' => $resultSet[$i]['grupoNome'],
            'subgrupos' => [
                [
                    'subgrupoURL'  => $resultSet[$i]['subgrupoURL'],
                    'subgrupoNome' => $resultSet[$i]['subgrupoNome']
                ]
            ]
        ];
    }
}

What is done: the resultset is traversed and, at each iteration, the keys are checked grupoNome and grupoURL are already present in the final array. If so, we place the other elements as sub-elements. Otherwise, we create a new index in the final array and fill it with the data from resultset.