递归查询—写法

WITH RecursiveCategories (parent_dir_id,dir_id ,dir_name , Level)
  AS
  (

   SELECT parent_dir_id, dir_id, dir_name, 0 AS Level
   FROM edms_directory
   WHERE dir_id = 0
   UNION ALL

   SELECT edms_directory.parent_dir_id, edms_directory.dir_id, edms_directory.dir_name,
        Level + 1
   FROM edms_directory
   INNER JOIN RecursiveCategories AS d
    ON edms_directory.parent_dir_id = d.dir_id
   
  )




select count(dir_id) from edms_document where dir_id in (
  Select dir_id From RecursiveCategories
) and is_deleted <> 'Y' and is_link <> 'Y'