获取修改的预定义树遍历模型（嵌套集）到<ul>中

我试图让我的数据是分层build立一个树遍历模型到一个<ul>为了显示在我的网站上。

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 = $row["rght"]; $p_left = $row["lft"]; $p_diff = $diff; } } $result.= "</ul>"; return $result; }

这是我的样品表：

 |ID | TITLE | lft| rght | |1 | Cat 1 | 1 | 16 | |18 | Cat 2 | 3 | 4 | |22 | Cat 3 | 5 | 6 | |28 | Cat 4 | 7 | 8 | |34 | Cat 5 | 9 | 9 | |46 | Cat 6 | 11 | 10 | |47 | Cat 7 | 13 | 12 | |49 | Cat 8 | 15 | 14 |

现在输出如下所示：

  <ul> <li>Cat 1</li> <li>Cat 2</li> <li>Cat 3</li> <li>Cat 4</li> <li>Cat 5</li> <li>Cat 6</li> <li>Cat 7</li> <li>Cat 8</li> </ul>

任何人都可以告诉我为什么或如何输出层次结构的列表？

相关主题

好吧，我们来做点赏金吧）

第0步 – 净化示例：
如前所述，您的示例数据已被破坏，因为它没有定义有效的嵌套集合。如果您从应用程序中获取这些数据，则应该检查插入/删除逻辑。

所以为了testing，我使用了一个消毒版本，如下所示：
（MySQL在这里，因为它是第一手）

 CREATE TABLE t_categories`( `id` INTEGER UNSIGNED NOT NULL AUTO_INCREMENT, `title` VARCHAR(45) NOT NULL, `lft` INTEGER UNSIGNED NOT NULL, `rght` INTEGER UNSIGNED NOT NULL, PRIMARY KEY (`id`) ); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 1',1,16); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 2',2,3); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 3',4,7); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 4',5,6); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 5',8,13); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 6',9,12); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 7',10,11); INSERT INTO t_categories (title, lft, rght) VALUES ('Cat 8',14,15);

步骤1 – 让数据库进行sorting
嵌套集主要是作为在数据库中存储树的方便方式发明的，因为它们使查询子树，父关系以及在这种情况下特别有趣的顺序和深度变得非常容易：

 SELECT node.title, (COUNT(parent.title) - 1) AS depth FROM t_categories AS node CROSS JOIN t_categories AS parent WHERE node.lft BETWEEN parent.lft AND parent.rght GROUP BY node.title ORDER BY node.lft

这将返回您的集合整齐有序，从根节点开始，并继续到前端的结束。最重要的是，它会将每个节点的深度作为正整数加起来，表示节点在根（0级）以下的级别。对于上面的示例数据，结果将是：

 title, depth 'Cat 1', 0 'Cat 2', 1 'Cat 3', 1 'Cat 4', 2 'Cat 5', 1 'Cat 6', 2 'Cat 7', 3 'Cat 8', 1

在代码中：

 // Grab ordered data $query = ''; $query .= 'SELECT node.title, (COUNT(parent.title) - 1) AS depth'; $query .= ' FROM t_categories AS node'; $query .= ' CROSS JOIN t_categories AS parent'; $query .= ' WHERE node.lft BETWEEN parent.lft AND parent.rght'; $query .= ' GROUP BY node.title'; $query .= ' ORDER BY node.lft'; $result = mysql_query($query); // Build array $tree = array(); while ($row = mysql_fetch_assoc($result)) { $tree[] = $row; }

结果数组如下所示：

 Array ( [0] => Array ( [title] => Cat 1 [depth] => 0 ) [1] => Array ( [title] => Cat 2 [depth] => 1 ) ... )

第2步 – 输出为HTML列表片段：

使用while循环：

 // bootstrap loop $result = ''; $currDepth = -1; // -1 to get the outer <ul> while (!empty($tree)) { $currNode = array_shift($tree); // Level down? if ($currNode['depth'] > $currDepth) { // Yes, open <ul> $result .= '<ul>'; } // Level up? if ($currNode['depth'] < $currDepth) { // Yes, close n open <ul> $result .= str_repeat('</ul>', $currDepth - $currNode['depth']); } // Always add node $result .= '<li>' . $currNode['title'] . '</li>'; // Adjust current depth $currDepth = $currNode['depth']; // Are we finished? if (empty($tree)) { // Yes, close n open <ul> $result .= str_repeat('</ul>', $currDepth + 1); } } print $result;

与recursion函数相同的逻辑：

 function renderTree($tree, $currDepth = -1) { $currNode = array_shift($tree); $result = ''; // Going down? if ($currNode['depth'] > $currDepth) { // Yes, prepend <ul> $result .= '<ul>'; } // Going up? if ($currNode['depth'] < $currDepth) { // Yes, close n open <ul> $result .= str_repeat('</ul>', $currDepth - $currNode['depth']); } // Always add the node $result .= '<li>' . $currNode['title'] . '</li>'; // Anything left? if (!empty($tree)) { // Yes, recurse $result .= renderTree($tree, $currNode['depth']); } else { // No, close remaining <ul> $result .= str_repeat('</ul>', $currNode['depth'] + 1); } return $result; } print renderTree($tree);

两者都会输出如下结构：

 <ul> <li>Cat 1</li> <li> <ul> <li>Cat 2</li> <li>Cat 3</li> <li> <ul> <li>Cat 4</li> </ul> </li> <li>Cat 5</li> <li> <ul> <li>Cat 6</li> <li> <ul> <li>Cat 7</li> </ul> </li> </ul> </li> <li>Cat 8</li> </ul> </li> </ul>

Nitpickersangular落：Questioner明确要求<ul> ，但是命令无序列表！来吧…
😉

更好的渲染树function ，为我工作（ PHP函数准备在jsTree jQuery插件中使用HTML源代码 ），而不是亨里克·欧宝的：

 function MyRenderTree ( $tree = array(array('name'=>'','depth'=>'')) ){ $current_depth = 0; $counter = 0; $result = '<ul>'; foreach($tree as $node){ $node_depth = $node['depth']; $node_name = $node['name']; $node_id = $node['category_id']; if($node_depth == $current_depth){ if($counter > 0) $result .= '</li>'; } elseif($node_depth > $current_depth){ $result .= '<ul>'; $current_depth = $current_depth + ($node_depth - $current_depth); } elseif($node_depth < $current_depth){ $result .= str_repeat('</li></ul>',$current_depth - $node_depth).'</li>'; $current_depth = $current_depth - ($current_depth - $node_depth); } $result .= '<li id="c'.$node_id.'"'; $result .= $node_depth < 2 ?' class="open"':''; $result .= '><a href="#"><ins>&nbsp;</ins>'.$node_name.'</a>'; ++$counter; } $result .= str_repeat('</li></ul>',$node_depth).'</li>'; $result .= '</ul>'; return $result;}

结果HTML：

 <ul> <li id="c1" class="open"><a href="#"><ins>&nbsp;</ins>ELECTRONICS</a> <ul> <li id="c2" class="open"><a href="#"><ins>&nbsp;</ins>TELEVISIONS</a> <ul> <li id="c3"><a href="#"><ins>&nbsp;</ins>TUBE</a></li> <li id="c4"><a href="#"><ins>&nbsp;</ins>LCD</a></li> <li id="c5"><a href="#"><ins>&nbsp;</ins>PLASMA</a> <ul> <li id="c14"><a href="#"><ins>&nbsp;</ins>PLASMA1</a></li> <li id="c15"><a href="#"><ins>&nbsp;</ins>PLASMA2</a></li> </ul> </li> </ul> </li> <li id="c6" class="open"><a href="#"><ins>&nbsp;</ins>PORTABLE ELECTRONICS</a> <ul> <li id="c7"><a href="#"><ins>&nbsp;</ins>MP3 PLAYERS</a> <ul> <li id="c8"><a href="#"><ins>&nbsp;</ins>FLASH</a></li> </ul> </li> <li id="c9"><a href="#"><ins>&nbsp;</ins>CD PLAYERS</a></li> <li id="c10"><a href="#"><ins>&nbsp;</ins>2 WAY RADIOS</a></li> </ul> </li> </ul> </li> </ul>

有一个PEAR包处理嵌套集： DB_NestedSet 。
您可能也对“ pipe理MySQL中的分层数据 ”这篇文章感兴趣。

这应该是你在找什么：

 function getCats($left = null, $right = null) { $sql = array(); $result = null; if (isset($left) === true) { $sql[] = 'lft >= ' . intval($left); } if (isset($right) === true) { $sql[] = 'rght <= ' . intval($right); } if (empty($sql) === true) { $sql[] = 'lft = 1'; } $sql = 'SELECT * FROM t_categories WHERE ' . implode(' AND ', $sql) . ';'; if ($rs = C_DB::fetchRecordset($sql)) { // you need to make sure that the query returns // something to correctly display the ULs if (empty($rs) === false) { $result .= '<ul>' . "\n"; while ($row = C_DB::fetchRow($rs)) { $result .= '<li>' . $row['title'] . '</li>' . "\n"; $result .= getCats($row['lft'], $row['rght']); } $result .= '</ul>' . "\n"; } } return $result; }

要获得嵌套树的HTML，你应该这样做：

 echo getCats();

请注意，你的嵌套示例看起来不正确，你也应该确保我没有犯任何错误调用你的C_DB类，我不知道，因为我不熟悉它。

简单地循环通过结果将做到：

 $sql = "SELECT node.name, (COUNT(parent.name) - 1) AS depth FROM nested_category AS node, nested_category AS parent WHERE node.lft BETWEEN parent.lft AND parent.rgt GROUP BY node.name ORDER BY node.lft"; $query_result = mysql_query($sql) $result = "<ul>"; $currDepth = 0; while($row = mysql_fetch_assoc($query_result)) { if($row['depth'] > $currDepth) { $result .= "<li><ul>"; // open sub tree if level up } if($row['depth'] < $currDepth) { $result .= str_repeat("</ul></li>", $currDepth - $row['depth']); // close sub tree if level down } $result .= "<li>$row['name']</li>"; // Always add node $currDepth = $row['depth']; } $result .= "</ul>"; echo $result;

 $linaje=''; $lastnode=''; $sides['izq']=array(); $sides['der']=array(); $print = '<ul>'; foreach ($array as $key1 => $value1){ //Proyectos if(strpos($info[$key1]['linaje'],'-') !== false) $compare = strstr($info[$key1]['linaje'],'-',true); else $compare = $info[$key1]['linaje']; if($linaje != ''){ if ($linaje != $compare){ $linaje= $compare; $sides['izq']=array(); $sides['der']=array(); //for($i=1;$i <= substr_count($lastnode,'`')-substr_count($value1,'`');$i++) //$print .= '</ul></li>'; } } if ($lastnode != '') for($i=1;$i<= substr_count($lastnode,'`')-substr_count($value1,'`');$i++) $print .= '</ul></li>'; if (count($sides['der'])>0) if ($sides['der'][count($sides['der'])-1] > $info[$key1]['der']) $print .= '<ul>'; $print .= '<li><a href="#'.$info[$key1]['id'].'#'.$info[$key1]['linaje'].'">'.substr($value1,substr_count($value1,'`')).'</a>'; if ($info[$key1]['der'] - $info[$key1]['izq'] == 1) $print .= '</li>'; if ($key1 == count($info)-1) for($i=1;$i <= substr_count($lastnode,'`')-1;$i++) $print .= '</ul></li>'; $sides['der'][] = $info[$key1]['der']; $sides['izq'][] = $info[$key1]['izq']; if ($linaje =='') $linaje = $info[$key1]['linaje']; $lastnode = $value1; } $print .= '</ul>'; echo $print;

不同之处在于你可以渲染X数量的树，这适用于我的一个项目。当我从DB获取行时，我使用char作为深度参考

我使用CROSS JOIN查询显示jsTree jQuery菜单; 一切都很好！现有的表格我添加了一个位置列。但是，当我定义位置并按位置sorting时，相应的项目没有正确分组。我想这是一个查询问题，尝试了很多组合，但没有成功。