PHP从平面数据集（从Mysql表）创建多维对象

以下是mysql表中的数据集：

使用MySQL嵌套集模型并不明显，因为我省略了

lft

和

rgt

列

+------+----------+--------------------------------+-------+
+ Id   | ParentId | Name                           | Level |
+------+----------+--------------------------------+-------+
| 1001 |     NULL | Computing                      |     0 |
| 1002 |     NULL | Cassettes & Vinyl              |     0 |
| 1003 |     1001 | CD Players                     |     1 |
| 1004 |     1002 | CD Writers                     |     1 |
| 1005 |     1003 | CD-ROM Drives                  |     2 |
| 1006 |     1004 | CDs                            |     2 |
+------+----------+--------------------------------+-------+

将其拉入二维数组：

<?php
$data = array(
          array('id' => 1001, 'ParentId' => NULL, 'Name' => 'Computing', 'Level' => 0),
          array('id' => 1002, 'ParentId' => NULL, 'Name' => 'Cassettes & Vinyl', 'Level' => 0),
          array('id' => 1003, 'ParentId' => 1001, 'Name' => 'CD Players', 'Level' => 1),
          array('id' => 1004, 'ParentId' => 1002, 'Name' => 'CD Writers', 'Level' => 1),
          array('id' => 1005, 'ParentId' => 1003, 'Name' => 'CD-ROM Drives', 'Level' => 2),
          array('id' => 1006, 'ParentId' => 1004, 'Name' => 'Computing', 'Level' => 3)
        );
?>

我一直在玩递归函数，运气不好

为什么此对象将用于创建Zend_导航。我不想在这个阶段使用XML文件，我更喜欢在数据库中进行分类管理

---

有什么想法吗？

这不一定是递归的工作，可以通过迭代轻松完成

<?php

$data = array(
  array('id' => 1001, 'ParentId' => NULL, 'Name' => 'Computing', 'Level' => 0),
  array('id' => 1002, 'ParentId' => NULL, 'Name' => 'Cassettes & Vinyl', 'Level' => 0),
  array('id' => 1003, 'ParentId' => 1001, 'Name' => 'CD Players', 'Level' => 1),
  array('id' => 1004, 'ParentId' => 1002, 'Name' => 'CD Writers', 'Level' => 1),
  array('id' => 1005, 'ParentId' => 1003, 'Name' => 'CD-ROM Drives', 'Level' => 2),
  array('id' => 1006, 'ParentId' => 1004, 'Name' => 'Computing', 'Level' => 3)
);

$index = array();
$tree  = array();

// step 1: build index (note that I use &$row references!) 
foreach ($data as &$row) {
  $index[$row['id']] = &$row;
  $row['children'] = array();
  if ($row['ParentId'] == NULL) {
    $tree[] = &$row;
  }
}

// step 2: link tree (references here as well!)
foreach ($data as &$row) {
  $index[$row['ParentId']]['children'][] = &$row;
}

print_r($tree);

?>

---

Id使用mysql\u fetch\u对象从数据库中提取数据，代码会变成什么？使用

mysql\u fetch\u assoc（）

怎么样？那就不那么麻烦了。除此之外，上面的代码非常简单。对你来说，做出必要的改变应该不难。

<?php

$data = array(
  array('id' => 1001, 'ParentId' => NULL, 'Name' => 'Computing', 'Level' => 0),
  array('id' => 1002, 'ParentId' => NULL, 'Name' => 'Cassettes & Vinyl', 'Level' => 0),
  array('id' => 1003, 'ParentId' => 1001, 'Name' => 'CD Players', 'Level' => 1),
  array('id' => 1004, 'ParentId' => 1002, 'Name' => 'CD Writers', 'Level' => 1),
  array('id' => 1005, 'ParentId' => 1003, 'Name' => 'CD-ROM Drives', 'Level' => 2),
  array('id' => 1006, 'ParentId' => 1004, 'Name' => 'Computing', 'Level' => 3)
);

$index = array();
$tree  = array();

// step 1: build index (note that I use &$row references!) 
foreach ($data as &$row) {
  $index[$row['id']] = &$row;
  $row['children'] = array();
  if ($row['ParentId'] == NULL) {
    $tree[] = &$row;
  }
}

// step 2: link tree (references here as well!)
foreach ($data as &$row) {
  $index[$row['ParentId']]['children'][] = &$row;
}

print_r($tree);

?>

Array
(
  [0] => Array
  (
    [id] => 1001
    [ParentId] => 
    [Name] => Computing
    [Level] => 0
    [children] => Array
    (
      [0] => Array
      (
        [id] => 1003
        [ParentId] => 1001
        [Name] => CD Players
        [Level] => 1
        [children] => Array
        (
          [0] => Array
          (
            [id] => 1005
            [ParentId] => 1003
            [Name] => CD-ROM Drives
            [Level] => 2
            [children] => Array
            (
            )
          )
        )
      )
    )
  )
  [1] => Array
  (
    [id] => 1002
    [ParentId] => 
    [Name] => Cassettes & Vinyl
    [Level] => 0
    [children] => Array
    (
      [0] => Array
      (
        [id] => 1004
        [ParentId] => 1002
        [Name] => CD Writers
        [Level] => 1
        [children] => Array
        (
          [0] => Array
          (
            [id] => 1006
            [ParentId] => 1004
            [Name] => Computing
            [Level] => 3
            [children] => Array
            (
            )
          )
        )
      )
    )
  )
)