PHP recursively implements infinite classification tree
The infinite level tree diagram can be said to be a distinctive feature of the infinite level column. Let’s take a look at two different writing methods.
1. Database design
CREATE TABLE `bg_cate` ( `cate_Id` int(30) unsigned NOT NULL AUTO_INCREMENT, `cate_ParentId` int(30) unsigned DEFAULT '0', `cate_Name` varchar(100) NOT NULL, `cate_Intro` varchar(500) DEFAULT NULL, `cate_Order` int(30) unsigned DEFAULT '0', `cate_Icon` varchar(100) DEFAULT NULL, PRIMARY KEY (`cate_Id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=34 ; -- -- 导出表中的数据 `bg_cate` -- INSERT INTO `bg_cate` (`cate_Id`, `cate_ParentId`, `cate_Name`, `cate_Intro`, `cate_Order`, `cate_Icon`) VALUES (4, 0, '往事如风', '记录往事', 0, 'icons/6.gif'), (5, 0, '水煮三国', '品位三国智慧', 0, 'icons/3.gif'), (2, 0, '技术学习', '平时学习的一些笔记，欢迎批评指正。', 0, 'icons/18.gif'), (3, 0, '生活点滴', '记录生活点滴', 0, 'icons/2.gif'), (6, 0, '栀子花开', '青春无限', 0, 'icons/8.gif'), (7, 0, '假日休闲', '悠闲、自在', 0, 'icons/24.gif'), (8, 2, 'html', 'html学习', 0, 'icons/1.gif'), (9, 2, 'css', 'css学习', 0, 'icons/1.gif'), (10, 2, 'php', 'php学习', 0, 'icons/18.gif'), (11, 10, 'php基础知识', 'php基础知识', 0, 'icons/1.gif'), (12, 10, 'oop', 'oop', 0, 'icons/1.gif'), (13, 10, 'php安全', '讲述php安全', 0, 'icons/1.gif'), (14, 10, 'seagull framework', 'seagull framework', 0, 'icons/1.gif'), (15, 2, 'javascript', 'javascript学习', 0, 'icons/1.gif'), (16, 2, '设计模式', NULL, 0, 'icons/1.gif'), (17, 2, '软件工程', '软件工程学习', 0, 'icons/1.gif'), (18, 3, '厦门生活', '厦门生活', 0, 'icons/8.gif'), (19, 3, '大学生活', '大学生活', 0, 'icons/8.gif'), (20, 3, '童年生活', '童年生活', 0, 'icons/15.gif'), (21, 19, '学习', '学习', 0, 'icons/1.gif'), (22, 19, '运动', '运动', 0, 'icons/16.gif'), (23, 19, '旅游', '旅游', 0, 'icons/24.gif'), (24, 22, '排球', '排球', 0, 'icons/9.gif'), (25, 22, '篮球', '篮球', 0, 'icons/9.gif'), (26, 22, '羽毛球', '羽毛球', 0, 'icons/9.gif'), (27, 22, '乒乓球', '乒乓球', 0, 'icons/9.gif');
2. Get the data from the database and put it into the array.
require_once './classes/MyDB.php'; $con = MyDB::singleton(); $sql = <<<SQL select * from bg_cate cate SQL; $data = $con->getAll($sql); //print_r($data);
I use the pear class library for database operations.
The data format of the final $data is as follows:
Array
(
[0] => Array
(
[cate_Id] => 4
[cate_ParentId] => 0
[cate_Name] => 往事如风
[cate_Intro] => 记录往事
[cate_Order] => 0
[cate_Icon] => icons/6.gif
)
[1] => Array
(
[cate_Id] => 5
[cate_ParentId] => 0
[cate_Name] => 水煮三国
[cate_Intro] => 品位三国智慧
[cate_Order] => 0
[cate_Icon] => icons/3.gif
)3. Convert the data from the previous step into a tree-shaped array
The code is as follows:
function getTree($data, $pId)
{
$tree = '';
foreach($data as $k => $v)
{
if($v['cate_ParentId'] == $pId)
{ //父亲找到儿子
$v['cate_ParentId'] = getTree($data, $v['cate_Id']);
$tree[] = $v;
//unset($data[$k]);
}
}
return $tree;
}
$tree = getTree($data, 0);The final output data format of $tree is:
Array
(
[0] => Array
(
[cate_Id] => 4
[cate_ParentId] =>
[cate_Name] => 往事如风
[cate_Intro] => 记录往事
[cate_Order] => 0
[cate_Icon] => icons/6.gif
)
[1] => Array
(
[cate_Id] => 5
[cate_ParentId] =>
[cate_Name] => 水煮三国
[cate_Intro] => 品位三国智慧
[cate_Order] => 0
[cate_Icon] => icons/3.gif
)
[2] => Array
(
[cate_Id] => 2
[cate_ParentId] => Array
(
[0] => Array
(
[cate_Id] => 8
[cate_ParentId] =>
[cate_Name] => html
[cate_Intro] => html学习
[cate_Order] => 0
[cate_Icon] => icons/1.gif
)4. Convert the tree array to html
The code is as follows:
function procHtml($tree)
{
$html = '';
foreach($tree as $t)
{
if($t['cate_ParentId'] == '')
{
$html .= "<li>{$t['cate_Name']}</li>";
}
else
{
$html .= "<li>".$t['cate_Name'];
$html .= procHtml($t['cate_ParentId']);
$html = $html."</li>";
}
}
return $html ? '<ul>'.$html.'</ul>' : $html ;
}
echo procHtml($tree);The code format of the output html is:
<ul>
<li>往事如风</li>
<li>水煮三国</li>
<li>技术学习
<ul>
<li>html</li>
<li>css</li>
<li>php
<ul>
<li>php基础知识</li>
<li>oop</li>
<li>php安全</li>5. Code integration
function getTree($data, $pId)
{
$html = '';
foreach($data as $k => $v)
{
if($v['cate_ParentId'] == $pId)
{ //父亲找到儿子
$html .= "<li>".$v['cate_Name'];
$html .= getTree($data, $v['cate_Id']);
$html = $html."</li>";
}
}
return $html ? '<ul>'.$html.'</ul>' : $html ;
}
echo getTree($data, 0); 6. Add CSS styles
##The second one is seen from open source websites, very very Introduction.
<?php
function genTree5($items) {
foreach ($items as $item)
$items[$item['pid']]['son'][$item['id']] = &$items[$item['id']];
return isset($items[0]['son']) ? $items[0]['son'] : array();
}
/**
* 将数据格式化成树形结构
* @author Xuefen.Tong
* @param array $items
* @return array
*/
function genTree9($items) {
$tree = array(); //格式化好的树
foreach ($items as $item)
if (isset($items[$item['pid']]))
$items[$item['pid']]['son'][] = &$items[$item['id']];
else
$tree[] = &$items[$item['id']];
return $tree;
}
$items = array(
1 => array('id' => 1, 'pid' => 0, 'name' => '江西省'),
2 => array('id' => 2, 'pid' => 0, 'name' => '黑龙江省'),
3 => array('id' => 3, 'pid' => 1, 'name' => '南昌市'),
4 => array('id' => 4, 'pid' => 2, 'name' => '哈尔滨市'),
5 => array('id' => 5, 'pid' => 2, 'name' => '鸡西市'),
6 => array('id' => 6, 'pid' => 4, 'name' => '香坊区'),
7 => array('id' => 7, 'pid' => 4, 'name' => '南岗区'),
8 => array('id' => 8, 'pid' => 6, 'name' => '和兴路'),
9 => array('id' => 9, 'pid' => 7, 'name' => '西大直街'),
10 => array('id' => 10, 'pid' => 8, 'name' => '东北林业大学'),
11 => array('id' => 11, 'pid' => 9, 'name' => '哈尔滨工业大学'),
12 => array('id' => 12, 'pid' => 8, 'name' => '哈尔滨师范大学'),
13 => array('id' => 13, 'pid' => 1, 'name' => '赣州市'),
14 => array('id' => 14, 'pid' => 13, 'name' => '赣县'),
15 => array('id' => 15, 'pid' => 13, 'name' => '于都县'),
16 => array('id' => 16, 'pid' => 14, 'name' => '茅店镇'),
17 => array('id' => 17, 'pid' => 14, 'name' => '大田乡'),
18 => array('id' => 18, 'pid' => 16, 'name' => '义源村'),
19 => array('id' => 19, 'pid' => 16, 'name' => '上坝村'),
);
echo "<pre class="brush:php;toolbar:false">";
print_r(genTree5($items));
print_r(genTree9($items));
//后者输出格式，前者类似，只是数组键值不一样，不过不影响数据结构
/*
Array
(
[0] => Array
(
[id] => 1
[pid] => 0
[name] => 江西省
[son] => Array
(
[0] => Array
(
[id] => 3
[pid] => 1
[name] => 南昌市
)
[1] => Array
(
[id] => 13
[pid] => 1
[name] => 赣州市
[son] => Array
(
[0] => Array
(
[id] => 14
[pid] => 13
[name] => 赣县
[son] => Array
(
[0] => Array
(
[id] => 16
[pid] => 14
[name] => 茅店镇
[son] => Array
(
[0] => Array
(
[id] => 18
[pid] => 16
[name] => 义源村
)
[1] => Array
(
[id] => 19
[pid] => 16
[name] => 上坝村
)
)
)
[1] => Array
(
[id] => 17
[pid] => 14
[name] => 大田乡
)
)
)
[1] => Array
(
[id] => 15
[pid] => 13
[name] => 于都县
)
)
)
)
)
[1] => Array
(
[id] => 2
[pid] => 0
[name] => 黑龙江省
[son] => Array
(
[0] => Array
(
[id] => 4
[pid] => 2
[name] => 哈尔滨市
[son] => Array
(
[0] => Array
(
[id] => 6
[pid] => 4
[name] => 香坊区
[son] => Array
(
[0] => Array
(
[id] => 8
[pid] => 6
[name] => 和兴路
[son] => Array
(
[0] => Array
(
[id] => 10
[pid] => 8
[name] =>
东北林业大学
)
[1] => Array
(
[id] => 12
[pid] => 8
[name] =>
哈尔滨师范大学
)
)
)
)
)
[1] => Array
(
[id] => 7
[pid] => 4
[name] => 南岗区
[son] => Array
(
[0] => Array
(
[id] => 9
[pid] => 7
[name] => 西大直街
[son] => Array
(
[0] => Array
(
[id] => 11
[pid] => 9
[name] =>
哈尔滨工业大学
)
)
)
)
)
)
)
[1] => Array
(
[id] => 5
[pid] => 2
[name] => 鸡西市
)
)
)
)*/php paging library download 2. php image processing library 3. Verification code library download 4. File upload class library 5. String processing class
6. Classification library 7.Database operation class library 8.ip class library 9.Cache class library 10.Template engine class library
php uses recursive method to achieve infinite classification
Exposing the principle of unlimited classification in PHP
Analysis of implementation method of unlimited classification in PHP
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