How to implement infinite classification in php

php method to implement Infinitus classification: first create a PHP sample file; then write logic code; then obtain subclasses from the top level downwards; finally, start from the subclasses and obtain their parent classes step by step upwards. Infinite classification can be achieved.

The operating environment of this article: windows7 system, PHP7.1 version, DELL G3 computer

PHP implementation of Infinitus classification graphic tutorial

Generally speaking, recursive or iterative methods are used to implement Infinitus classification. Friends, please take a look at the implementation method in this article.

1, Database design:

##2, Code:

The code is as follows:

/** 
 * @author koma 
 * @todo   PHP无限极分类 
 */ $cn = mysql_connect('localhost', 'root', '') or die(mysql_error()); 
mysql_select_db('t', $cn) or die(mysql_error()); 
mysql_query('set names utf8'); 
 /** 
 * 从顶层逐级向下获取子类 
 * @param number $pid 
 * @param array $lists 
 * @param number $deep 
 * @return array 
 */ function getLists($pid = 0, &$lists = array(), $deep = 1) { 
    $sql = 'SELECT * FROM category WHERE pid='.$pid; 
    $res = mysql_query($sql); 
    while ( ($row = mysql_fetch_assoc($res)) !== FALSE ) { 
        $row['catename'] = str_repeat('   ', $deep).'|---'.$row['catename']; 
        $lists[] = $row; 
        getLists($row['id'], $lists, ++$deep); //进入子类之前深度+1         --$deep; 
        //从子类退出之后深度-1    
         } 
    return $lists; 
} 
 function displayLists($pid = 0, $selectid = 1) { 
    $result = getLists($pid); 
    $str = &#39;<select>&#39;; 
    foreach ( $result as $item ) { 
        $selected = ""; 
        if ( $selectid == $item[&#39;id&#39;] ) { 
            $selected = &#39;selected&#39;; 
        } 
        $str .= &#39;<option &#39;.$selected.&#39;>&#39;.$item[&#39;catename&#39;].&#39;</option>&#39;; 
    } 
    return $str .= &#39;</select>&#39;; 
} /** 
 * 从子类开始逐级向上获取其父类 
 * @param number $cid 
 * @param array $category 
 * @return array: 
 */ function getCategory($cid, &$category = array()) { 
    $sql = &#39;SELECT * FROM category WHERE id=&#39;.$cid.&#39; LIMIT 1&#39;; 
    $result = mysql_query($sql); 
    $row = mysql_fetch_assoc($result); 
    if ( $row ) { 
        $category[] = $row; 
        getCategory($row[&#39;pid&#39;], $category); 
    } 
    krsort($category); //逆序,达到从父类到子类的效果     return $category; 
} 
 function displayCategory($cid) { 
    $result = getCategory($cid); 
    $str = ""; 
    foreach ( $result as $item ) { 
        $str .= &#39;<a href="&#39;.$item[&#39;id&#39;].&#39;">&#39;.$item[&#39;catename&#39;].&#39;</a>>&#39;; 
    } 
    return substr($str, 0, strlen($str) - 1); 
} 
 echo displayLists(0, 3); 
 echo displayCategory(13);

3, rendering:

Isn’t it very simple? Friends can use it directly without any copyright fees.

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