Nesting hierarchical data into an array - PHP (Codeigniter)

问题

I have been trying to solve this for while but its been a little difficult. the thing is, am trying nest the data from the table bellow into an array in the order by which they are related.

+-----+------+------------+
| uid | name | supermember|
+-----+------+------------+
|   1 | A    |      0     |
|   2 | B    |      1     |
|   3 | C    |      1     |
|   4 | D    |      2     |
|   5 | E    |      3     |
|   7 | G    |      3     |
|   9 | H    |      4     |
|  10 | I    |      4     |
|  11 | J    |      7     |
+-----+------+------------+

Here is what i have done:

public function getDataAsBinaryTree($id)
    {
        $this->db->where('uid', $id);
        $query = $this->db->get('binary_tbl');
        $result = [];
        if ($query->num_rows() > 0) {
            foreach ($query->result() as $k) {
                $result[$k->name] =  $this->tolevels($k->uid);
            }
         } else {
            $result = NULL;
         }
         return $result;  
    }   



    private function tolevels($id)
    {
        $this->db->where('supermember', $id);
        $query = $this->db->get('binary_tbl');
        $output = [];
        $count = $query->num_rows();
        if ($query->num_rows() > 0) {
            foreach ($query->result() as $key) {
                $output[$key->name] = (($count > 1) ? $this->tolevel($key->uid) : $this->tolevel($key->uid));
            }
        } 
        return $output;
    }

EXPECTED OUTPUT


array(
        'A' => array(
                'B' => array(
                    'D' => array(
                       'H' => 'H',
                        'I' => 'I'
                       )
                     ),
                 'C' => array(
                     'E' => null,
                      'G' => array(
                         'J' => 'J'
                        )
                   )
                )
            );

i want the returned data from these methods to be in key and value pair but it instead returned an array with only keys when i var_dump on the getDataAsBinaryTree(1) method. I think the problem is from the recursion but i just don't know how to get around it.

RESULT

array (size=1)
  'A' => 
    array (size=2)
      'B' => 
        array (size=1)
          'D' => 
            array (size=2)
              ...
      'C' => 
        array (size=2)
          'E' => 
            array (size=0)
              ...
          'G' => 
            array (size=1)
              ...

回答1:

Honestly, I don't understand your question completely, you should provide the structure of output code. But as your function getDataAsBinaryTree suggests you're trying to make a binary tree, if that's the case then this is the way to go.

public function getDataAsBinaryTree($id = false){

    // $this->db->where('uid', $id);
    $query  = $this->db->get('binary_tbl');
    $result = [];

    if ($query->num_rows() > 0) {
        foreach ($query->result() as $k) {
            $result[$k->name] =  $this->tolevels($k->uid);
        }
    } else {
       $result = NULL;
    }
    // return $result;
    echo '<pre>'; print_r($result);  
}

private function tolevels($id){

    $this->db->where('supermember', $id);

    $query  = $this->db->get('binary_tbl');
    $output = [];
    $count  = $query->num_rows();

    if ($query->num_rows() > 0) {
        foreach ($query->result() as $key) {
            // $output[$key->name] = ($count > 0) ? $this->tolevels($key->uid) : $key->uid;
            $output[$key->name] = $key->uid;
            if($count > 0){ $this->tolevels($key->uid); };
        }
    } 
    return $output;
}

OUTPUT

Array
(
    [A] => Array
        (
            [B] => 2
            [C] => 3
        )

    [B] => Array
        (
            [D] => 4
        )

    [C] => Array
        (
            [E] => 5
            [G] => 6
        )

    [D] => Array
        (
            [H] => 7
            [I] => 8
        )

    [E] => Array
        (
        )

    [G] => Array
        (
        )

    [H] => Array
        (
            [J] => 9
        )

    [I] => Array
        (
        )

    [J] => Array
        (
        )

)

Hope, this helps you. :)

来源：https://stackoverflow.com/questions/61545812/nesting-hierarchical-data-into-an-array-php-codeigniter

标签

php

sql

codeigniter

recursion