如何创建“多维树菜单”使用PHP和SQL？ [英] How to create "multidimensional tree menu" using PHP and SQL?
问题描述
我搜索了一段时间，但在google和其他论坛找不到任何东西。但它是奇怪的，因为它是我们大学的流行任务。
我有一个任务：
创建多维树菜单（深度未定义，可以是4或7，取决于用户的意愿），应该有添加新元素，编辑，删除和显示整个树结构使用PHP，SQL和最小CSS p>
树的视觉示例：
+菜单pre>
+ Shop
+ Tshirts
+ Yellow
+ Green
+裤子$ b $ b +论坛
+想法
您可以看到它有4个深度级别：
Menu-> Shop-> tshirt->黄色
但是我必须让用户可以添加他想要的级别和元素。
有任何例子， SQL结构应该保持？
谢谢！解决方案您想要使用ID和parentID来保存DB中的每个元素如果没有这样的父存在，则为null）。
考虑下面的数据库结果：
----------------------------
| id | parentID |文本|
| ---- | ---------- | ---------- |
| 1 | null |项目＃1 |
| 2 | 5 |项目＃2 |
| 3 | 2 |项目＃3 |
| 4 | 2 |项目＃4 |
| 5 | null |项目＃5 |
| 6 | 5 |项目＃6 |
| 7 | 3 |项目＃7 |
| 8 | 5 |项目＃8 |
| 9 | 1 |项目＃9 |
| 10 | 7 |项目＃10 |
----------------------------
考虑下面的数组（可能来自一个数据库结果 - 重要的是，ID是键，你可以简单地将你的数据库结果转换为类似下面的需要的键是parentID）：
$ menu = array（
1 = ='Item＃1'，'parentID'=> null），
2 => array（'text'=>'Item＃2'，'parentID'=> 5） b $ b 3 => array（'text'=>'Item＃3'，'parentID'=> 2），
4 => array（'text'=& '，'parentID'=> 2），
5 => array（'text'=>'Item＃5' array（'text'=>'Item＃6'，'parentID'=> 5），
7 => array（'text'=>'Item＃7'，'parentID'=> ; 3），
8 => array（'text'=>'Item＃8'，'parentID'=> 5），
9 = ;'Item＃9'，'parentID'=> 1），
10 => array（'text'=>'Item＃10'，'parentID'=& 7），
）;
并将其变成树形结构：
<？php
$ addedAsChildren = array（）;
foreach（$ menu = $ id =>& $ menuItem）{//注意我们使用引用，所以我们不要重复数组
if（！empty menuItem ['parentID']））{
$ addedAsChildren [] = $ id; //它应该从根中删除，但我们会这样做后
if（！isset（$ menu [$ menuItem ['parentID']] ['children']））{
$ menu [$ menuItem ['parentID']] ['children'] = array（$ id =>& $ menuItem）; //&意味着我们使用REFERENCE
} else {
$ menu [$ menuItem ['parentID']] ['children'] [$ id] =& $ menuItem; //&意味着我们使用REFERENCE
}
}
unset（$ menuItem ['parentID']）; //我们不再需要parentID
}
unset（$ menuItem）; // unset the reference
foreach（$ addedAsChildren as $ itemID）{
unset（$ menu [$ itemID]）; //从根中删除它，所以它只在['children']子阵列中
}
使用这个新数组，我们可以使用简单的递归函数在
ul..li中输出：echo makeTree（$ menu）;
function makeTree（$ menu）{
$ tree ='< ul>';
foreach（$ menu as $ id => $ menuItem）{
$ tree。='< li>'。 $ menuItem ['text'];
if（！empty（$ menuItem ['children']））{
$ tree。= makeTree（$ menuItem ['children']）;
}
$ tree。='< / li>';
}
return $ tree。 '< / ul>';
}
导致：
< ul>< li>第1项< ul>< li>第9项< / li>< / ul>< / li>项目＃5< ul>< li>项目＃2< ul>< li>项目＃3< ul>项目＃7< li>项目＃10< / li> < / ul>< / li>< li>项目＃6< / li>< / ul>< / li>< / li>< ; li>项目＃8< / li>< / ul>< / li>< / ul&
..并呈现：
img src =https://i.stack.imgur.com/8q5UR.pngalt =enter image description here>
I searched for awhile, but couldn't find anything on google and other forums. But it's weird because it's popular task in our university. So I think this post might help other too with same issue.
I got a task:
"Create multidimensional tree menu (depth is undefined, could be 4 or 7, depending on user's will), there should be options like adding new element, editing, deleting and showing the whole tree structure. Using PHP, SQL and minimal CSS."
Visual example of a tree:
+Menu +Shop +Tshirts +Yellow +Green +Pants +Forum +IdeasAs you can see it's 4 depth levels:
Menu->Shop->tshirt->yellowBut I have to make it so that user could add as many levels as he wants and elements to it.Is there any examples to it and what SQL structure should I keep on? Thank you!
解决方案You want to save each element in the DB with an ID and a parentID (that can be null if no such parent exists). The PHP is your "biggest" problem, but references are your huge friend here for turning a flat structure into a tree structure.
Consider the following DB result:
---------------------------- | id | parentID | text | |----|----------|----------| | 1 | null | Item #1 | | 2 | 5 | Item #2 | | 3 | 2 | Item #3 | | 4 | 2 | Item #4 | | 5 | null | Item #5 | | 6 | 5 | Item #6 | | 7 | 3 | Item #7 | | 8 | 5 | Item #8 | | 9 | 1 | Item #9 | | 10 | 7 | Item #10 | ----------------------------Consider the following array (that could be from a DB result - it's important that the ID is the key, though. You can simply transform your DB result into something like the following (the only needed key is "parentID"):
$menu = array( 1 => array('text' => 'Item #1', 'parentID' => null), 2 => array('text' => 'Item #2', 'parentID' => 5), 3 => array('text' => 'Item #3', 'parentID' => 2), 4 => array('text' => 'Item #4', 'parentID' => 2), 5 => array('text' => 'Item #5', 'parentID' => null), 6 => array('text' => 'Item #6', 'parentID' => 5), 7 => array('text' => 'Item #7', 'parentID' => 3), 8 => array('text' => 'Item #8', 'parentID' => 5), 9 => array('text' => 'Item #9', 'parentID' => 1), 10 => array('text' => 'Item #10', 'parentID' => 7), );And to turn it into a tree structure:
<?php $addedAsChildren = array(); foreach ($menu as $id => &$menuItem) { // note that we use a reference so we don't duplicate the array if (!empty($menuItem['parentID'])) { $addedAsChildren[] = $id; // it should be removed from root, but we'll do that later if (!isset($menu[$menuItem['parentID']]['children'])) { $menu[$menuItem['parentID']]['children'] = array($id => &$menuItem); // & means we use the REFERENCE } else { $menu[$menuItem['parentID']]['children'][$id] = &$menuItem; // & means we use the REFERENCE } } unset($menuItem['parentID']); // we don't need parentID any more } unset($menuItem); // unset the reference foreach ($addedAsChildren as $itemID) { unset($menu[$itemID]); // remove it from root so it's only in the ['children'] subarray }With this new array we can use a simply recursive function to output it all in a
ul..lisense:echo makeTree($menu); function makeTree($menu) { $tree = '<ul>'; foreach ($menu as $id => $menuItem) { $tree .= '<li>' . $menuItem['text']; if (!empty($menuItem['children'])) { $tree .= makeTree($menuItem['children']); } $tree .= '</li>'; } return $tree . '</ul>'; }Resulting in:
<ul><li>Item #1<ul><li>Item #9</li></ul></li><li>Item #5<ul><li>Item #2<ul><li>Item #3<ul><li>Item #7<ul><li>Item #10</li></ul></li></ul></li><li>Item #4</li></ul></li><li>Item #6</li><li>Item #8</li></ul></li></ul>..and rendered:
这篇关于如何创建“多维树菜单”使用PHP和SQL？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
