【www.bbyears.com--php常用代码】
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 $a = array("AAAAAA" => array(
"aaaaaa" => array(
"111111",
"222222",
"333333"
),
"bbbbbb" => array(
"111111",
"222222",
"333333"
),
"cccccc" => array(
"111111",
"222222",
"333333"
),
),
"BBBBBB" => array(
"aaaaaa" => array(
"111111",
"222222",
"333333"
),
"bbbbbb"=> array(
"111111",
"222222",
"333333"
),
"cccccc"=> array(
"111111",
"222222",
"333333"
),
),
"CCCCCC" => array(
"aaaaaa"=> array(
"111111",
"222222",
"333333"
),
"bbbbbb"=> array(
"111111",
"222222",
"333333"
),
"cccccc" => array(
"111111",
"222222",
"333333"
),
),
);
foreach ($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//查询
$dsql->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, "顶级栏目", 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);
/**
* 显示树,把所有的节点都显示出来。
* 1、先得到根结点的左右值（默认根节点的title为“顶级目录”）。
* 2、查询左右值在根节点的左右值范围内的记录，并且根据左值排序。
* 3、如果本次记录右值大于前次记录的右值则为子分类，输出时候加空格。
* @return array
**/
function display_tree(){
//获得root左边和右边的值
$arr_lr = $this->category->where("title = "顶级栏目"")->find();
//print_r($arr_lr);
if($arr_lr){
$right = array();
$arr_tree = $this->category->query("SELECT id, type, title, rgt FROM category WHERE lft >= ". $arr_lr["lft"] ." AND lft <=".$arr_lr["rgt"]." ORDER BY lft");
foreach($arr_tree as $v){
if(count($right)){
while ($right[count($right) -1] < $v["rgt"]){
array_pop($right);
}
}
$title = $v["title"];
if(count($right)){
$title = "|-".$title;
}
$arr_list[] = array("id" => $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。