类别层次结构 (PHP/MySQL) [英] Category Hierarchy (PHP/MySQL)

问题描述

我正在尝试从层次结构中的 MySQL 数据库中获取我的所有类别和子类别:

我的结果应该是这样的(只是例子):

<块引用>

1. 猫 A
   • 子类别 1
     • Sub_Sub_Cat 1
     • Sub_Sub_Cat 2
   • Sub_Cat 2
2. 猫 B
3. 猫 C
4. ...

MySQL 代码:

如果不存在则创建表`categories`(`category_id` mediumint(8) 无符号 NOT NULL AUTO_INCREMENT，`parent_id` mediumint(8) unsigned NOT NULL DEFAULT '0' COMMENT 'for sub-categories'主键(`category_id`)) 引擎=InnoDB 默认字符集=utf8 ;

简单地说，如何使用 PHP 代码使其成为一个层次结构?

解决方案

使用邻接表模型时，可以一次性生成结构.

取自 One Pass父子数组结构(2007 年 9 月；Nate Weiner 着):

$refs = array();$list = 数组();$sql = "SELECT item_id, parent_id, name FROM items ORDER BY name";/** @var $pdo \PDO */$result = $pdo->query($sql);foreach ($result 作为 $row){$ref = &$refs[$row['item_id']];$ref['parent_id'] = $row['parent_id'];$ref['name'] = $row['name'];如果($row['parent_id'] == 0){$list[$row['item_id']] = &$ref;}别的{$refs[$row['parent_id']]['children'][$row['item_id']] = &$ref;}}

从链接的文章中，这里有一个片段，用于创建输出列表.它是递归的，如果一个节点有子节点，它会再次调用自己来构建子树.

function toUL(array $array){$html = '
'.PHP_EOL;foreach ($array 作为 $value){$html .='
'.$value['name'];if (!empty($value['children'])){$html .= toUL($value['children']);}$html .='
'.PHP_EOL;}$html .= '</ul>'.PHP_EOL;返回 $html;}

相关问题:

• 如何从对象的数组记录集中获取嵌套的 HTML 列表?

I am trying to get my all categories and sub-categories from MySQL database in a hierarchy:

My result should be like that (just example):

1. Cat A
   • Sub-Cat 1
     • Sub_Sub_Cat 1
     • Sub_Sub_Cat 2
   • Sub_Cat 2
2. Cat B
3. Cat C
4. ...

MySQL code:

CREATE TABLE IF NOT EXISTS `categories` (
   `category_id` mediumint(8) unsigned NOT NULL AUTO_INCREMENT,
   `parent_id` mediumint(8) unsigned NOT NULL DEFAULT '0' COMMENT 'for sub-categories'
  PRIMARY KEY (`category_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 ;

Simply, how can get it in a hirarchy with PHP codes?

解决方案

When using an adjacency list model, you can generate the structure in one pass.

Taken from One Pass Parent-Child Array Structure (Sep 2007; by Nate Weiner):

$refs = array();
$list = array();

$sql = "SELECT item_id, parent_id, name FROM items ORDER BY name";

/** @var $pdo \PDO */
$result = $pdo->query($sql);

foreach ($result as $row)
{
    $ref = & $refs[$row['item_id']];

    $ref['parent_id'] = $row['parent_id'];
    $ref['name']      = $row['name'];

    if ($row['parent_id'] == 0)
    {
        $list[$row['item_id']] = & $ref;
    }
    else
    {
        $refs[$row['parent_id']]['children'][$row['item_id']] = & $ref;
    }
}

From the linked article, here's a snippet to create a list for output. It is recursive, if there a children for a node, it calls itself again to build up the subtree.

function toUL(array $array)
{
    $html = '<ul>' . PHP_EOL;

    foreach ($array as $value)
    {
        $html .= '<li>' . $value['name'];
        if (!empty($value['children']))
        {
            $html .= toUL($value['children']);
        }
        $html .= '</li>' . PHP_EOL;
    }

    $html .= '</ul>' . PHP_EOL;

    return $html;
}

Related Question:

• How to obtain a nested HTML list from object's array recordset?

这篇关于类别层次结构 (PHP/MySQL)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！