Question

我从MySQL数据库返回一个页面列表及其父页面，并将所有结果放入一个数组中，如下所示，每个结果都是一个数组，其中包含论坛的父级，名称和ID（数组页面的键）也与页面ID相同）。

为了模型和应用，还有一些其他参数。

“根页”的父级为0
没有孤立的网页

因此，MySQL查询将返回此数据集。

pages=>
     [1] => array(id=>1, 
                  parent=>0, 
                  name=>Hello World)
     [2] => array(id=>1, 
                  parent=>1, 
                  name=>Child of Hello World)
     [3] => array(id=>1, 
                  parent=>0, 
                  name=>Brother of Hello World)
     [4] => array(id=>4, 
                  parent=>2, 
                  name=Grand-child of Hello World)
     [6] => array(id=>6, 
                  parent=>4, 
                  name=Great-grand-child of Hello World)

然后我想将数组转换为看起来像这样的东西

pages=>
     [1] => id=>1, 
            name=>Hello World
            children=>

                [2] => id=>1
                       name=>Child of Hello World
                       children=>

                           [4] => 
                             id=>4
                             name=> Grand-child of Hello World)
                             children=>

                                 [6] => 
                                   id=>6
                                   name=> Great-grand-child of Hello World
                                   children= null

     [3] => array(id=>1, 
                  name=>Brother of Hello World
                  children=>null

基本上，我想将一个线性数组转换为嵌套的多维数组，以便我可以打印我的站点地图。

它需要是一个递归的解决方案。有超过700页，最多5或6个级别。

我只想做1个mysql查询。不是700所以请不要给我一个基于mysql的解决方案。

Answer 1

<?php

$pages = array();
$pages[1] = array('id' => 1, 'parent' => 0, 'name' => 'Hello World');
$pages[2] = array('id' => 1, 'parent' => 1, 'name' => 'Child of Hello World');
$pages[3] = array('id' => 1, 'parent' => 0, 'name' => 'Brother of Hello World');
$pages[4] = array('id' => 4, 'parent' => 2, 'name' => 'Grand-child of Hello World');
$pages[6] = array('id' => 6, 'parent' => 4, 'name' => 'Great-grand-child of Hello World');

$children = array();
foreach($pages as $key => $page){
    $parent = (int)$page['parent'];
    if(!isset($children[$parent]))
        $children[$parent] = array();
    $children[$parent][$key] = array('id' => $page['id'], 'name' => $page['name']);
}

$new_pages = recursive_append_children($children[0], $children);

function recursive_append_children($arr, $children){
    foreach($arr as $key => $page)
        if(isset($children[$key]))
            $arr[$key]['children'] = recursive_append_children($children[$key], $children);
    return $arr;
}

print_r($new_pages);

?>

输出：

Array
(
    [1] => Array
        (
            [id] => 1
            [name] => Hello World
            [children] => Array
                (
                    [2] => Array
                        (
                            [id] => 1
                            [name] => Child of Hello World
                            [children] => Array
                                (
                                    [4] => Array
                                        (
                                            [id] => 4
                                            [name] => Grand-child of Hello World
                                            [children] => Array
                                                (
                                                    [6] => Array
                                                        (
                                                            [id] => 6
                                                            [name] => Great-grand-child of Hello World
                                                        )

                                                )

                                        )

                                )

                        )

                )

        )

    [3] => Array
        (
            [id] => 1
            [name] => Brother of Hello World
        )
)

Answer 2

这是一个构建树的快速递归函数。请注意，它并不是很好（一个原因是因为它没有删除已经添加到树中的项目，所以每次递归它都会通过整个列表） - 但它应该足以让你开始。

function buildTree($itemList, $parentId) {
  // return an array of items with parent = $parentId
  $result = array();
  foreach ($itemList as $item) {
    if ($item['parent'] == $parentId) {
      $newItem = $item;
      $newItem['children'] = buildTree($itemList, $newItem['id']);
      $result[] = $newItem;
    }
  }

  if (count($result) > 0) return $result;
  return null;
}

$myTree = buildTree($myArray, 0);

PHP从列表构建递归数组

2 个答案: