相关疑难解决方法(0)

我试图将我的数据分层设置为树遍历模型到<ul>,以便在我的网站上显示.

这是我的代码:

function getCats($) {
  // retrieve all children of $parent
  $query = "SELECT max(rght) as max from t_categories";
  $row = C_DB::fetchSingleRow($query);
  $max = $row["max"];
  $result ="<ul>";
  $query = "SELECT * from t_categories where lft >=0 and rght <= $max";
  if($rs = C_DB::fetchRecordset($query)){
    $p_right ="";
    $p_left ="";
    $p_diff="";          
    while($row = C_DB::fetchRow($rs)){
      $diff = $row["rght"] -$row["lft"];

      if($diff == $p_diff){
        $result.= "<li>".$row['title']."</li>";
      }elseif (($row["rght"] - $row["lft"] > 1) && ($row["rght"] > $p_right)){
        $result. "<ul>";
        $result.= "<li>".$row['title']."</li>";

      }else{
        $result.= "<li>".$row['title']."</li>";
      } 

      $p_right = …

我有这张桌子:

CREATE TABLE `categories` (
  `id` int(11) NOT NULL auto_increment,
  `category_id` int(11) default NULL,
  `root_id` int(11) default NULL,
  `name` varchar(100) collate utf8_unicode_ci NOT NULL,
  `lft` int(11) NOT NULL,
  `rht` int(11) NOT NULL,
  PRIMARY KEY  (`id`),
  KEY `category_id` (`category_id`),
  KEY `lft` (`lft`,`rht`),
  KEY `root_id` (`root_id`)
) 

基于这个问题: 将修改后的预订树遍历模型(嵌套集)转换为<ul>

不同的是,我在一张桌子上有很多树.每行都有一个代表其父级及其顶级父级的外键:category_id和root_id.我还有基于这个例子的lft和rht字段:http://articles.sitepoint.com/article/hierarchical-data-database/2

基于这些行:

INSERT INTO `categories` VALUES(1, NULL, NULL, 'Fruits', 1, 14);
INSERT INTO `categories` VALUES(2, 1, 1, 'Apple', 2, 3);
INSERT INTO `categories` VALUES(3, 1, 1, 'Orange', 4, 9);
INSERT INTO …