1，递归找出指定用户的指定层级的下级用户

    1. /**
    2.  * 找到指定用户的指定级别的下级用户
    3.  * @param $pidStr 指定用户id
    4.  * @param $num 指定第几个下级
    5.  * @return string 返回下级id组成的字符串
    6.  */
    7. function getSonsId($pidStr,$num){
    8.     $sql = "SELECT user_id FROM ".$GLOBALS['ecs']->table('users')." WHERE parent_id IN (".$pidStr.")";
    9.     $sonArr = $GLOBALS['db']->getAll($sql);
    10.     foreach($sonArr as $key => $val){
    11.         $sonArr[$key] = $val["user_id"];
    12.     }
    13.     $sonStr = implode(',',$sonArr);
    14.     if($num == 1){
    15.         return $sonStr;
    16.     }else{
    17.         $num--;
    18.         return getSonsId($sonStr,$num);
    19.     }
    20. }

    2，递归找当前产品最顶级分类

    1. //找到该商品的分类
    2.   $sql = "SELECT cat_id FROM ecs_goods WHERE goods_id";
    3.   $scat_id = $db->getOne($sql);
    4.   $bigCatId = getBigCatByCatId($scat_id)  
    6. //根据商品分类找到其所属的最顶级分类
    7. function getBigCatByCatId($cat_id){
    8.   $sql = "SELECT parent_id FROM ecs_category WHERE cat_id = ".$cat_id;
    9.   $fcat_id = $db->getOne($sql);
    10.   if($fcat_id == '0'){
    11.     return $cat_id;
    12.   }else{
    13.     return getBigCatByCatId($fcat_id);
    14.   }
    15. }