PHP实现查询多级分类的程序代码

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(
        &＃39;aaaaaa&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
        &＃39;bbbbbb&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
        &＃39;cccccc&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
    ) ,
    &＃39;BBBBBB&＃39; => array(
        &＃39;aaaaaa&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
        &＃39;bbbbbb&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
        &＃39;cccccc&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
    ) ,
    &＃39;CCCCCC&＃39; => array(
        &＃39;aaaaaa&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
        &＃39;bbbbbb&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
        &＃39;cccccc&＃39; => array(
            &＃39;111111&＃39;,
            &＃39;222222&＃39;,
            &＃39;333333&＃39;
        ) ,
    ) ,
);
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[&＃39;big&＃39;]] = $arr[&＃39;small&＃39;]; 
    } 
    ***/
?>

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(&＃39;parentlist&＃39;);
$array = array();
$parentlist = array();
while ($rs = $dsql->getObject(&＃39;parentlist&＃39;)) {
    if ($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[&＃39;parentid&＃39;] == $arr[&＃39;id&＃39;]) {
                $list[$key][&＃39;children&＃39;][] = $value;
                unset($array[$k]);
            }
        }
    }
    foreach ($list as $key => $arr) {
        if (is_array($arr[&＃39;children&＃39;]) && count($arr[&＃39;children&＃39;]) > 0) {
            $list[$key][&＃39;children&＃39;] = cat_options($list[$key][&＃39;children&＃39;], $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 &＃39;1为文章类型2为产品类型3为下载类型&＃39;,  
`title` varchar(50) NOT NULL,  
`lft` int(11) NOT NULL,  
`rgt` int(11) NOT NULL,  
`lorder` int(11) NOT NULL COMMENT &＃39;排序&＃39;,  
`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, &＃39;顶级栏目&＃39;, 1, 18, 1, 1261964806),  
(2, 1, &＃39;公司简介&＃39;, 14, 17, 50, 1264586212),  
(3, 1, &＃39;新闻&＃39;, 12, 13, 50, 1264586226),  
(4, 2, &＃39;公司产品&＃39;, 10, 11, 50, 1264586249),  
(5, 1, &＃39;荣誉资质&＃39;, 8, 9, 50, 1264586270),  
(6, 3, &＃39;资料下载&＃39;, 6, 7, 50, 1264586295),  
(7, 1, &＃39;人才招聘&＃39;, 4, 5, 50, 1264586314),  
(8, 1, &＃39;留言板&＃39;, 2, 3, 50, 1264586884),  
(9, 1, &＃39;总裁&＃39;, 15, 16, 50, 1267771951);

category->where("title = &＃39;顶级栏目&＃39;")->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[&＃39;lft&＃39;] . " AND lft <=" . $arr_lr[&＃39;rgt&＃39;] . " ORDER BY lft");
        foreach ($arr_tree as $v) {
            if (count($right)) {
                while ($right[count($right) - 1] <$v[&＃39;rgt&＃39;]) {
                    array_pop($right);
                }
            }
            $title = $v[&＃39;title&＃39;];
            if (count($right)) {
                $title = &＃39;|-&＃39; . $title;
            }
            $arr_list[] = array(
                &＃39;id&＃39; => $v[&＃39;id&＃39;],
                &＃39;type&＃39; => $type,
                &＃39;title&＃39; => str_repeat(&＃39; &＃39;, count($right)) . $title,
                &＃39;name&＃39; => $v[&＃39;title&＃39;]
            );
            $right[] = $v[&＃39;rgt&＃39;];
        }
        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。