如何将平面数组排序为多维树

Question

我有一个表格，例如

id    catagory      suboff

1     software       0
2     programming    1
3     Testing        1
4     Designing      1
5     Hospital       0
6     Doctor         5
7     Nurses         5
9     Teaching       0
10    php programming 2
11    .net programming 2

如何编写代码以根据 suboff 获取多维数组中的所有这些信息，如下所示，

-software
--programming
---php programming
--- .net programming
--testing
--designing
-hospital 
--doctor
--nurses
-teaching

Answer 1

假设 MySQL 作为您的数据库引擎：

// We'll need two arrays for this
$temp = $result = array();

// Get the data from the DB
$table = mysql_query("SELECT * FROM table");

// Put it into one dimensional array with the row id as the index
while ($row = mysql_fetch_assoc($table)) {
  $temp[$row['id']] = $row;
}

// Loop the 1D array and create the multi-dimensional array
for ($i = 1; isset($temp[$i]); $i++) {
  if ($temp[$i]['suboff'] > 0) {
    // This row has a parent
    if (isset($temp[$temp[$i]['suboff']])) {
      // The parent row exists, add this row to the 'children' key of the parent
      $temp[$temp[$i]['suboff']]['children'][] =& $temp[$i];
    } else {
      // The parent row doesn't exist - handle that case here
      // For the purposes of this example, we'll treat it as a root node
      $result[] =& $temp[$i];
    }
  } else {
    // This row is a root node
    $result[] =& $temp[$i];
  }
}

// unset the 1D array
unset($temp);

// Here is the result
print_r($result);

使用 引用 来完成这样的工作。

Answer 2

演示：http://ideone.com/vk4po

$array = array(
array('1','software','0'),
array('2','programming','1'),
array('3','Testing','1'),
array('4','Designing','1'),
array('5','Hospital','0'),
array('6','Doctor','5'),
array('7','Nurses','5'),
array('9','Teaching','0'),
array('10','php programming','2'),
array('11','.net programming','2')
);

function menu_sort($results, $master = 0)
{

    $open = array();
    $return = NULL;

    foreach($results as $result)
    {
        if($result[2] == $master){

            if(!$open){
                $return .= '<ul>';
                $open = true;
            }

            $return .= '<li>'.$result[1];

            $return .= menu_sort($results, $result[0]);
            $return .= '</li>';

        }
    }

    if($open)
        $return .= '</ul>';

    return $return;

}

echo menu_sort($array);

结果...

<前><代码>软件
编程
PHP编程
.net 编程
测试
设计
医院
医生
护士
教学

Answer 3

我的做法是：

1. 首先您需要解析该表。我想你可以自己做；如果没有，谷歌“正则表达式”，它们是你的朋友。

2. 您正在使用的数据结构是经典的树。您将需要两个数组来使用它。首先是一个节点数组，$nodes，其中键是节点 ID，值是节点名称，以及 $links，其中每个键是父节点，每个value 是一个子数组（$links[$id][] = $suboff 对于每个元素就足够了）。

3. 现在你必须递归地下降你拥有的树。您引入一个具有如下签名的函数：

   函数 print_node( $nodeID, $level = 1 )
   

   此函数应该使用 $level 填充破折号打印节点本身（存储在 $nodes 中的信息），并调用自身来渲染所有子节点。它们将依次渲染所有子节点等。您只需为顶级节点调用此函数即可。

Answer 4

此类将平面类别数组转换为结构化树数组：

<?php

/**
 * Creates a structured tree out of a flat category list
 */
class CategoryTree {

  /**
   *
   * @var array
   */
  protected $categories = array();

  /**
   *
   * @var array
   */
  protected $tree = array();

  /**
   * Default constructor
   * @param array $categories 
   */
  function __construct(array $categories) {
    $this->categories = $categories;
  }

  /**
   * Process a subtree
   * @param array $categories
   * @param integer $parentId
   * @return array 
   */
  protected function getSubtree(array $categories, $parentId = 0) {
    $tree = array();

    foreach($categories as $category) {
      if($category['suboff'] == $parentId) {
        $tree[$category['id']] = $category;
        $tree[$category['id']]['children'] = $this->getSubtree($categories, $category['id']);
      }
    }

    return $tree;
  }

  /**
   * Get the category tree as structured array
   * @return array 
   */
  public function getTree() {
    if(empty($this->tree)) {
      $this->tree = $this->getSubtree($this->categories, 0);
    }
    return $this->tree;
  }

  /**
   * Get the category tree as string representation
   * @return string
   */
  public function __toString() {
    return "<pre>" . print_r($this->getTree(), true) . "</pre>";
  }

}


// Now, use the class with the givven data:

$categories = array(
  array(
    'id' => 1,
    'category' => 'software',
    'suboff' => 0
  ),
  array(
    'id' => 2,
    'category' => 'programming',
    'suboff' => 1
  ),
  array(
    'id' => 3,
    'category' => 'Testing',
    'suboff' => 1
  ),
  array(
    'id' => 4,
    'category' => 'Designing',
    'suboff' => 1
  ),
  array(
    'id' => 5,
    'category' => 'Hospital',
    'suboff' => 0
  ),
  array(
    'id' => 6,
    'category' => 'Doctor',
    'suboff' => 5
  ),
  array(
    'id' => 7,
    'category' => 'Nurses',
    'suboff' => 5
  ),
  array(
    'id' => 9,
    'category' => 'Teaching',
    'suboff' => 0
  ),
  array(
    'id' => 10,
    'category' => 'php programming',
    'suboff' => 2
  ),
  array(
    'id' => 11,
    'category' => '.net programming',
    'suboff' => 2
  )
);

$myTree = new CategoryTree($categories);
echo $myTree;

?>

Answer 5

这是我刚刚为我的应用程序编写的内容，它就像一个魅力:)

$array = [
    'i' => ['key' => 'i', 'name' => 'php programming', 'parent' => 'b'], 
    'g' => ['key' => 'g', 'name' => 'Nurses', 'parent' => 'e'],
    'j' => ['key' => 'j', 'name' => '.net programming', 'parent' => 'b'], 
    'b' => ['key' => 'b', 'name' => 'programming', 'parent' => 'a'],
    'a' => ['key' => 'a', 'name' => 'software', 'parent' => 'asd'],
    'c' => ['key' => 'c', 'name' => 'Testing', 'parent' => 'a'], 
    'd' => ['key' => 'd', 'name' => 'Designing', 'parent' => 'a'], 
    'e' => ['key' => 'e', 'name' => 'Hospital', 'parent' => 'asd'],  
    'f' => ['key' => 'f', 'name' => 'Doctor', 'parent' => 'e'], 
    'h' => ['key' => 'h', 'name' => 'Teaching'],  
];

function getAsTree(array &$array)
{
    foreach ($array as $key => $item) {
        if (isset($item['parent']) && isset($array[$item['parent']])) {
            $array[$item['parent']]['children'][] = $item;
            unset($array[$key]);
            return getAsTree($array);
        }
    }

    return $array;
}

这是结果：

--- a：软件
------ b：编程
--------- 一：php编程
--------- j：.net 编程
------ c：测试
------ d：设计
--- e：医院
------ g：护士
------ f：医生
--- h：教学

Answer 6

恕我直言，逻辑是：

1. 获取所有根元素（软件、医院等）
2. Foreach 根获取子元素（对于您将进行编程、测试和设计的软件）
3. 将子元素添加为子数组
4. 在您刚刚添加的子数组上递归循环

Answer 7

您需要将整个表读入内存并将其转换为一棵树，其中每个节点都可以用其相应的 ID 号进行标识。然后对树进行预序遍历并将其打印出来。

Answer 8

在 PHP wenn 中，我从数据库获取数据：

"SELECT* FROM Table WHERE suboff LIKE 0"
foreach(item..)
   "SELECT* FROM Table WHERE suboff LIKE item.ID"
       foreach(item2..)
          $result[item][item2]

Answer 9

这是一种不同的方法，应该很容易理解。它要求您将表按 suboff 排序，即

SELECT * FROM table ORDER BY suboff

假设结果存储在 $table 中，您可以使用这个非常简洁的 php 代码：

// this will hold the result
$tree = array();
// used to find an entry using its id
$lookup = array();
foreach($table as $row){
  if($row['suboff'] === 0){
    // this has no parent, add it at base level
    $tree[$row['category']] = array();
    // store a reference
    $lookup[$row['id']] =& $tree[$row['category']];
  }else{
    // find the right parent, add the category
    $lookup[$row['suboff']][$row['category']] = array();
    // store a reference
    $lookup[$row['id']] =& $lookup[$row['suboff']][$row['category']];
  }
}

Answer 10

这个解决方案对我来说效果很好。

$array = array(
    array('1','software','0'),
    array('2','programming','1'),
    array('3','Testing','1'),
    array('4','Designing','1'),
    array('5','Hospital','0'),
    array('6','Doctor','5'),
    array('7','Nurses','5'),
    array('9','Teaching','0'),
    array('10','php programming','2'),
    array('11','.net programming','2')
);

$newArray = getTree($array);

function getTree( $rows, $suboff = 0) {

    $return = array();

    foreach($rows as $row) {

        if($row[2] == $suboff){

            $newrow = $row;

            $subs = $this->getTree($rows, $row[0]);

            if ( !empty($subs) ) {
                $newrow['subs'] = $subs;
            }

            $return[] = $newrow;

        }
    }

    return $return;

}