将两个关联数组转换为一个多维数组 PHP

Question

I have 2 associative arrays resulting from 2 queries in JSON format below:

{
  "competence": [
    {
      "id": "21",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla"
    },
    {
      "id": "11",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla"
    },
    {
      "id": "26",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla"
    }
  ],
  "schedule": [
    {
      "id": "34",
      "parent_id": "21",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla"
    },
    {
      "id": "33",
      "parent_id": "21",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla"
    },
    {
      "id": "32",
      "parent_id": "11",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla"
    },
    {
      "id": "31",
      "parent_id": "26",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla"
    }
  ]
}

These 2 arrays above generated by this code:

<?php

$queryCompetence = mysqli_query($con, "SELECT `id`, `title`, `description`, `image` FROM `competence` ORDER BY `title` ASC");
$querySchedule = mysqli_query($con, "SELECT `id`, `id_competence`, `title`, `description`, `image` FROM `schedule` ORDER BY `created_date` DESC");

$competence = array();
$schedule = array();

while ($row = mysqli_fetch_assoc($queryCompetence)) {
    $competence[] = array(
        'id' => $row['id'],
        'title' => $row['title'],
        'description' => $row['description'],
        'image' => $row['image'],
    );
}

while ($row = mysqli_fetch_assoc($querySchedule)) {
    $schedule[] = array(
        'id' => $row['id'],
        'parent_id' => $row['id_competence'],
        'title' => $row['title'],
        'description' => $row['description'],
        'image' => $row['image'],
    );
}

$response['competence'] = $competence;
$response['schedule'] = $schedule;

echo json_encode($response);
die();

?>

I need to make a multidimensional array in php that will output the JSON below:

{
  "competence": [
    {
      "id": "21",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla",
      "schedule": [
        {
          "id": "34",
          "parent_id": "21",
          "title": "blabla",
          "description": "blabla",
          "image": "blabla"
        },
        {
          "id": "33",
          "parent_id": "21",
          "title": "blabla",
          "description": "blabla",
          "image": "blabla"
        }
      ]
    },
    {
      "id": "11",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla",
      "schedule": [
        {
          "id": "32",
          "parent_id": "11",
          "title": "blabla",
          "description": "blabla",
          "image": "blabla"
        },
        {
          "id": "33",
          "parent_id": "21",
          "title": "blabla",
          "description": "blabla",
          "image": "blabla"
        }
      ]
    },
    {
      "id": "26",
      "title": "blabla",
      "description": "blabla",
      "image": "blabla",
      "schedule": [
        {
          "id": "31",
          "parent_id": "26",
          "title": "blabla",
          "description": "blabla",
          "image": "blabla"
        }
      ]
    }
  ]
}

How do I achieve this? I've been searching around on the net but seems like getting no luck. Any help will be much appreciated.

Thank you.

Answer 1

You just need to iterate over the $schedule array, inserting its values into $competence where the id value in $competence matches the parent_id value in $schedule :

foreach ($schedule as $s) {
    // find the parent_id in $competence
    if (($key = array_search($s['parent_id'], array_column($competence, 'id'))) !== false) {
        $competence[$key]['schedule'][] = $s;
    }
}
$response = array('competence' => $competence);

Demo on 3v4l.org

Answer 2

I would index the competences by ID when looping over them, then simply adjust its array when looping over the schedules.

This way, you don't need to loop over anything twice:

while ($row = mysqli_fetch_assoc($queryCompetence)) {
  // `$competence` is now indexed by ID
  $competence[$row['id']] = [
    'id' => $row['id'],
    'title' => $row['title'],
    'description' => $row['description'],
    'image' => $row['image'],
  ];
}

while ($row = mysqli_fetch_assoc($querySchedule)) {
  $schedule[$row['id']] = [
    'id' => $row['id'],
    'parent_id' => $row['id_competence'],
    'title' => $row['title'],
    'description' => $row['description'],
    'image' => $row['image'],
  ];
  // If the parent competence exists, add the schedule to it
  if (array_key_exists($row['id_competence'], $competence)) {
    $competence[$row['id_competence']]['schedule'][] = $schedule[$row['id']];
  }
}

Then, if you don't need/want the IDs as keys when json_encode -ing back, you can use array_values :

$response['competence'] = array_values($competence);
$response['schedule'] = array_values($schedule);

Answer 3

I hope this will work like charm.

    $a = [
    [
          "id"=> "21",
          "title"=> "blabla",
          "description"=> "blabla",
          "image"=> "blabla"
        ],
        [
          "id"=> "11",
          "title"=> "blabla",
          "description"=> "blabla",
          "image"=> "blabla"
        ],
        [
          "id"=> "26",
          "title"=> "blabla",
          "description"=> "blabla",
          "image"=> "blabla"
        ]
    ];

    $b = [
        [ "id"=> "34",
          "parent_id"=> "21",
          "title"=> "blabla",
          "description"=> "blabla",
          "image"=> "blabla"
        ],
        [
          "id"=> "33",
          "parent_id"=> "21",
          "title"=> "blabla",
          "description"=> "blabla",
          "image"=> "blabla"
        ],
        [
          "id"=> "32",
          "parent_id"=> "11",
          "title"=> "blabla",
          "description"=> "blabla",
          "image"=> "blabla"
        ],
       [
          "id"=> "31",
          "parent_id"=> "26",
          "title"=> "blabla",
          "description"=> "blabla",
          "image"=> "blabla"
        ]
    ];


    $final = [];

    foreach($a as $key => $val)
    {
        $final[$key] = $val;
        foreach($b as $key1 => $val1)
        {

            if($val['id'] == $val1['parent_id'])
            {
                $final[$key]['schedule'][$key1] = $val1;
            }
        }
    }

$t = [];
$t['competence'] = $final;
echo "<pre>";
print_r(json_encode($t));