Erp系统常用递归，查类目树，查上级，查下级

1、无限极往上获取平台类目树信息

　　数据结构：商品类目id《category_id，商品类目父id《parent_id

　　数据需求：根据传入最低层类目id，获取所有上级类目信息（包含自己）

　　代码如下：

 1     // 无限极往上获取平台类目树信息
 2     public function platformCategoryVerify($platform, $site_code, $platform_category_id, $tree)
 3     {
 4         $apCategories_info = ApCategories::where([["category_id" , $platform_category_id],["platform" , $platform],["site_code" , $site_code]])->first(["category_id", "category_name", "parent_id", "level"]);
 5         if(!empty($apCategories_info->category_id)){
 6             $tree[] = $apCategories_info->toArray();
 7             $tree = $this->platformCategoryVerify($platform, $site_code, $apCategories_info->parent_id, $tree); //此处加“$tree = ” 是递归的关键，不然会导致 $tree数组，被覆盖
 8         }
 9         return $tree;
10     }