php - mysql + php 检索带路径的叶子节点

Question

我有一张这样的 table 。

+-----------+-----------+-----------+-----------+-----------+-----------+
|id         | parent_id | name      | order     | status    | date_add  |
+-----------+-----------+-----------+-----------+-----------+-----------+
|1          | 0         | shoes     | 1         | 1         | 2011-04-02|
+-----------+-----------+-----------+-----------+-----------+-----------+
|2          | 1         | male      | 2         | 1         | 2011-04-02|
+-----------+-----------+-----------+-----------+-----------+-----------+
|3          | 1         | female    | 3         | 1         | 2011-04-02|
+-----------+-----------+-----------+-----------+-----------+-----------+
|4          | 3         | red shoes | 4         | 1         | 2011-04-02|
+-----------+-----------+-----------+-----------+-----------+-----------+

我只想选择叶子节点及其路径。

我想得出的结果如下:

+------+-------------------------------------+
| 2    | shoes/male                          |
+------+-------------------------------------+
| 4    | shoes/female/red shoes              |
+------+-------------------------------------+

如果这样不仅sql还可以php+sql

请帮帮我。

Answer 1

使用 PHP 打印出所有最后一个子节点的 ID 和路径的非常简单的解决方案，因为我不知道在 MySQL 中执行此操作的方法。希望这对您有所帮助!

function getChildren($parent= "", $x = 0) {
   $sql = "SELECT id, name FROM recurr WHERE parentId = $x";
   $rs = mysql_query($sql);
   //echo "Name: $parent has ". mysql_num_rows($rs)." children<br/>";
   while ($obj = mysql_fetch_object($rs)) {
      if (hasChildren($obj->id)) {
         getChildren($parent."/".$obj->name, $obj->id);
      } else {
         echo $obj->id .", ".$parent."/".$obj->name."<br/>";
      }
   }
}

function hasChildren($x) {
   $sql = "SELECT * FROM recurr WHERE parentId = $x";
   $rs = mysql_query($sql);
   if (mysql_num_rows($rs) > 0) {
      return true;
   } else {
      return false;
   }
}

要运行只需调用:

getChildren();