将树数组结构转换为关联数组，每个数组中有额外的字段用于痕迹

Question

我的表结构是这样的：

id |类别| parent |

See image of table for categories

我的模态代码：

public function getData($table) { return $this->db->select('*')->get($table)->result_array(); }

我得到一个这样的数组：

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => Mobile Phones
            [parent] => 0
            [date] => 2017-05-16 08:55:22
            [slug] => mobile-phones
        )

    [1] => Array
        (
            [id] => 2
            [name] => Samsung
            [parent] => 1
            [date] => 2017-05-16 08:55:29
            [slug] => samsung
        )

    [2] => Array
        (
            [id] => 3
            [name] => Apple
            [parent] => 1
            [date] => 2017-05-16 18:07:56
            [slug] => apple
        )

    [3] => Array
        (
            [id] => 4
            [name] => Huawei
            [parent] => 1
            [date] => 2017-05-16 18:08:10
            [slug] => huawei
        )

    [4] => Array
        (
            [id] => 5
            [name] => HTC
            [parent] => 1
            [date] => 2017-05-16 18:08:22
            [slug] => htc
        )

    [5] => Array
        (
            [id] => 6
            [name] => OnePlus
            [parent] => 1
            [date] => 2017-05-16 18:08:33
            [slug] => oneplus
        )

    [6] => Array
        (
            [id] => 7
            [name] => LG
            [parent] => 1
            [date] => 2017-05-16 18:08:44
            [slug] => lg
        )

    [7] => Array
        (
            [id] => 8
            [name] => BlackBerry
            [parent] => 1
            [date] => 2017-05-16 18:08:55
            [slug] => blackberry
        )

    [8] => Array
        (
            [id] => 9
            [name] => Motorola
            [parent] => 1
            [date] => 2017-05-16 18:09:14
            [slug] => motorola
        )

    [9] => Array
        (
            [id] => 10
            [name] => Google
            [parent] => 1
            [date] => 2017-05-16 18:09:52
            [slug] => google
        )
    )

但我希望得到如下数组：

Array
(
    [0] => Array
        (

            [id] => 1
            [name] => Mobile Phones
            [parent] => 0
            [date] => 2017-05-16 08:55:22
            [slug] => mobile-phones
            [root_category] => null
        )

    [1] => Array
        (
            [id] => 2
            [name] => Samsung
            [parent] => 1
            [date] => 2017-05-16 08:55:29
            [slug] => samsung
            [root_category] => Mobile Phones

        )

    [2] => Array
        (
            [id] => 3
            [name] => android
            [parent] => 2
            [date] => 2017-05-16 18:07:56
            [slug] => android
            [root_category] => Mobile Phones > Samsung

        )

    [3] => Array
        (
            [id] => 4
            [name] => Huawei
            [parent] => 3
            [date] => 2017-05-16 18:08:10
            [slug] => huawei
            [root_category] => Mobile Phones > Samsung > android
        )

    [4] => Array
        (
            [id] => 5
            [name] => HTC
            [parent] => 1
            [date] => 2017-05-16 18:08:22
            [slug] => htc
            [root_category] => Mobile Phones
        )

    [5] => Array
        (
            [id] => 6
            [name] => OnePlus
            [parent] => 1
            [date] => 2017-05-16 18:08:33
            [slug] => oneplus
            [root_category] => Mobile Phones 
        )

    [6] => Array
        (
            [id] => 7
            [name] => LG
            [parent] => 1
            [date] => 2017-05-16 18:08:44
            [slug] => lg
            [root_category] => Mobile Phones 
        )

    [7] => Array
        (
            [id] => 8
            [name] => Men Fashion
            [parent] => 0
            [date] => 2017-05-16 18:08:55
            [slug] => men-fashion
            [root_category] => null
        )

    [8] => Array
        (
            [id] => 9
            [name] => shirt
            [parent] => 8
            [date] => 2017-05-16 18:09:14
            [slug] => shirt
            [root_category] => Men fashion
        )

    [9] => Array
        (
            [id] => 10
            [name] => T shirt
            [parent] => 9
            [date] => 2017-05-16 18:09:52
            [slug] => google
            [root_category] => Men Fashion > shirt
        )
}

顺便说一下，我正在使用codeigniter。

Answer 1

从数据库逻辑制作层​​次结构不是一个好习惯。

数据库表结构已足以存储父目录。

你需要有一个函数来递归调用它。

如果您的目标是创建面包屑，我假设您需要从最低层级爬升，直到parent值为=。

function display_sub($id=0)
{
    $breadcrumb = [];

    // I assume your these are your model and function name.
    $category = $this->item_model->get_category($id);

    if($category['parent'] != 0)
    {

        // if parent not 0, add the name to $breadcrumb array,
        // then do another run of this function 
        // but take this menu's parent id as parameter
        array_push($breadcrumb,$row['name']);
        $this->display_sub($row['parent']);

    } else {

        // if parent already 0, it's finish the job.
        // and you can reverse it and display as intended.
        return $breadcrumb;
    }
}