PHP实现查询多级分类的程序代码

无限级分类是我们常用见的一个程序方法了,原理是得到有层级关系的数组,就是*是*分类,然后每个分类中有个children子数组,记录它的子分类,这样一级一级的分级数组.

算法的数据库结构设计最为简单,category表中一个字段id,一个字段fid(父id),这样可以根据WHERE id = fid来判断上一级内容,运用递归至最顶层.

我们先查出数组,代码如下:

 array(
        'aaaaaa' => array(
            '111111',
            '222222',
            '333333'
        ) ,
        'bbbbbb' => array(
            '111111',
            '222222',
            '333333'
        ) ,
        'cccccc' => array(
            '111111',
            '222222',
            '333333'
        ) ,
    ) ,
    'BBBBBB' => array(
        'aaaaaa' => array(
            '111111',
            '222222',
            '333333'
        ) ,
        'bbbbbb' => array(
            '111111',
            '222222',
            '333333'
        ) ,
        'cccccc' => array(
            '111111',
            '222222',
            '333333'
        ) ,
    ) ,
    'CCCCCC' => array(
        'aaaaaa' => array(
            '111111',
            '222222',
            '333333'
        ) ,
        'bbbbbb' => array(
            '111111',
            '222222',
            '333333'
        ) ,
        'cccccc' => array(
            '111111',
            '222222',
            '333333'
        ) ,
    ) ,
);
foreach ($a as $k => $v) {
    echo $k . "
";
    // if(is_array($v)){
    foreach ($v as $key => $val) {
        echo "  " . $key . "
";
        //     }
        if (is_array($val)) {
            foreach ($val as $kkk => $vall) {
                echo "    " . $vall . "
";
            }
        }
    }
    echo "
";
}
/*******mysql查询无限级分类的代码******/
/***
   $sql = "SELECT a.Title AS big, b.Title AS small  
            FROM largeTitle AS a LEFT JOIN smallTitle  AS b ON  a.ID=b.LargeID"; 
             
    $a = array(); 
     
    $r = mysql_query($sql); 
     
    while( $arr = mysql_fetch_array($r)){ 
        $a[$arr['big']] = $arr['small']; 
    } 
    ***/
?>

好了下面先读取数据库然后再递归读出.

分类表,比如category,字段有 id,parentid,title,代码如下:

SetQuery("SELECT * FROM category ORDER BY sortorder ASC");
$dsql->Execute('parentlist');
$array = array();
$parentlist = array();
while ($rs = $dsql->getObject('parentlist')) {
    if ($rs->parentid == 0) {
        $parentlist[$rs->id] = (array)$rs;
    } else {
        $array[$rs->id] = (array)$rs;
    }
}
$parentlist = cat_options($parentlist, $array); //我们求的结果数组
//$list父级分类的数组
//$array是除父级分类外的全部分类的数组
function cat_options(&$list, &$array) {
    foreach ($list as $key => $arr) {
        foreach ($array as $k => $value) {
            if ($value['parentid'] == $arr['id']) {
                $list[$key]['children'][] = $value;
                unset($array[$k]);
            }
        }
    }
    foreach ($list as $key => $arr) {
        if (is_array($arr['children']) && count($arr['children']) > 0) {
            $list[$key]['children'] = cat_options($list[$key]['children'], $array);
        }
    }
    return $list;
}
?>

其它的方法,设置fid字段类型为varchar,将父类id都集中在这个字段里,用符号隔开,比如:1,3,6,这样可以比较容易得到各上级分类的ID,而且在查询分类下的信息的时候,可以使用:SELECT * FROM category WHERE pid LIKE "1,3%",代码如下:

--  
-- 表的结构 `category`  
--  
CREATE TABLE IF NOT EXISTS `category` (  
`id` int(11) NOT NULL AUTO_INCREMENT,  
`type` int(11) NOT NULL COMMENT '1为文章类型2为产品类型3为下载类型',  
`title` varchar(50) NOT NULL,  
`lft` int(11) NOT NULL,  
`rgt` int(11) NOT NULL,  
`lorder` int(11) NOT NULL COMMENT '排序',  
`create_time` int(11) NOT NULL,  
PRIMARY KEY (`id`)  
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=10 ;  
--  
-- 导出表中的数据 `category`  
--  
INSERT INTO `category` (`id`, `type`, `title`, `lft`, `rgt`, `lorder`, `create_time`) VALUES  
(1, 1, '*栏目', 1, 18, 1, 1261964806),  
(2, 1, '公司简介', 14, 17, 50, 1264586212),  
(3, 1, '新闻', 12, 13, 50, 1264586226),  
(4, 2, '公司产品', 10, 11, 50, 1264586249),  
(5, 1, '荣誉资质', 8, 9, 50, 1264586270),  
(6, 3, '资料下载', 6, 7, 50, 1264586295),  
(7, 1, '人才招聘', 4, 5, 50, 1264586314),  
(8, 1, '留言板', 2, 3, 50, 1264586884),  
(9, 1, '总裁', 15, 16, 50, 1267771951);

category->where("title = '*栏目'")->find();
    //print_r($arr_lr);
    if ($arr_lr) {
        $right = array();
        $arr_tree = $this->category->query("SELECT id, type, title, rgt FROM category WHERE lft >= " . $arr_lr['lft'] . " AND lft  $v['id'],
                'type' => $type,
                'title' => str_repeat(' ', count($right)) . $title,
                'name' => $v['title']
            );
            $right[] = $v['rgt'];
        }
        return $arr_list;
    }
}
?>

好了 只要这样所有的分类都可以一次性查询出来了,而不用通过递归了.

永久链接：

转载随意！带上文章地址吧。