function genTree5($items) { foreach ($items as $item) $items[$item['pid']]['son'][$item['id']] = &$items[$item['id']]; return isset($items[0]['son']) ? $items[0]['son'] : array(); }
9行代码的
function genTree9($items) { $tree = array(); //格式化好的树 foreach ($items as $item) if (isset($items[$item['pid']])) $items[$item['pid']]['son'][] = &$items[$item['id']]; else $tree[] = &$items[$item['id']]; return $tree; }
先取数据后格式化输出
取出的数组格式如下:
$items = array( 1 => array('id' => 1, 'pid' => 0, 'name' => '江西省'), 2 => array('id' => 2, 'pid' => 0, 'name' => '黑龙江省'), 3 => array('id' => 3, 'pid' => 1, 'name' => '南昌市'), 4 => array('id' => 4, 'pid' => 2, 'name' => '哈尔滨市'), 5 => array('id' => 5, 'pid' => 2, 'name' => '鸡西市'), 6 => array('id' => 6, 'pid' => 4, 'name' => '香坊区'), 7 => array('id' => 7, 'pid' => 4, 'name' => '南岗区'), 8 => array('id' => 8, 'pid' => 6, 'name' => '和兴路'), 9 => array('id' => 9, 'pid' => 7, 'name' => '西大直街'), 10 => array('id' => 10, 'pid' => 8, 'name' => '东北林业大学'), 11 => array('id' => 11, 'pid' => 9, 'name' => '哈尔滨工业大学'), 12 => array('id' => 12, 'pid' => 8, 'name' => '哈尔滨师范大学'), 13 => array('id' => 13, 'pid' => 1, 'name' => '赣州市'), 14 => array('id' => 14, 'pid' => 13, 'name' => '赣县'), 15 => array('id' => 15, 'pid' => 13, 'name' => '于都县'), 16 => array('id' => 16, 'pid' => 14, 'name' => '茅店镇'), 17 => array('id' => 17, 'pid' => 14, 'name' => '大田乡'), 18 => array('id' => 18, 'pid' => 16, 'name' => '义源村'), 19 => array('id' => 19, 'pid' => 16, 'name' => '上坝村'), );
from:www.oschina.net/code/snippet_173183_11767
二叉树表设计方式
http://www.phpro.org/tutorials/Managing-Hierarchical-Data-with-PHP-and-MySQL.html