php - PHP多级菜单

Question

我有一个这样的主题表:

id
title
parent_id
full_path

full_path 用于查找父级递归。像这样:

+----+-----------+-----------+-----------+
| 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 |
+----+-----------+-----------+-----------+

我怎样才能得到这样的递归数组:

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 创建多级菜单吗？

Answer 1

您可以使用下面的代码来执行此操作。请记住，这是可行的，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​​阵列上使用此方法。

<?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);
?>