问题描述

我有一个这样的主题表:

I have a subject table like this:

id
title
parent_id
full_path

full_path 用于以递归方式查找父级.像这样:

full_path is for finding parent as recursive. Like this:

+----+-----------+-----------+-----------+
| id | title     | full_path | parent_id |
+----+-----------+-----------+-----------+
| 40 | home      | 40        |         0 |
| 41 | myhome1   | 41        |         0 |
| 42 | ****      | 40-42     |        40 |
| 43 | *****     | 41-43     |        41 |
| 44 | ***       | 44        |         0 |
| 45 | ****      | 45        |         0 |
| 46 | *****     | 46        |         0 |
| 49 | ******    | 49        |         0 |
| 50 | **** **   | 40-42-50  |        42 |
| 51 | **** **   | 40-42-51  |        42 |
| 52 | **** **   | 40-42-52  |        42 |
| 53 | *******   | 40-53     |        40 |
| 54 | ****      | 40-54     |        40 |
| 55 | ***       | 41-55     |        41 |
| 56 | **** **** | 40-42-56  |        42 |
| 57 | *******   | 44-57     |        44 |
+----+-----------+-----------+-----------+

我如何获得这样的递归数组:

How i can get an recursive array like this:

array
(
    40 => array
    (
        42 => array
        (
            50,51,52,etc.
        ),
        53,
        54
    )
    41 => array
    (
        43,
        55,
    ),
    44 => array
    (
        57,
    ),
    etc...
)

我可以使用 full_path 来创建多级菜单吗?

Can I use full_path for create multilevel menu?

推荐答案

您可以使用下面的代码来执行此操作.请记住，这是有效的，因为您的主题数组将非常小并且发生的递归将是最小的.不要在大型​​数组上使用这种方法.

You could use the code below to do this. Keep in mind that this works because your subjects array will be very small and the recursion that happens will be minimal. Dont use this approach on large arrays.

<?php
$query = "SELECT id, parent_id FROM subjects";
//execute with your prefered method, eg mysqli

$rows = array();
while($row = $result->fetch_array(MYSQLI_ASSOC))
{
  $rows[] = $row;
}

function getChildren($p) {
  global $rows;
  $r = array();
  foreach($rows as $row) {
    if ($row['parent_id']==$p) {
      $r[$row['id']] = getChildren($row['id']);
    }
  }
  return $r;
}

$final = getChildren(0);
?>

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