SQL查詢無限層級結構的全部下級，全部上級

無限層級結構的table1表，Id（主鍵）,ParentId（父級id）查詢某個Id的全部下級或全部上級，使用WITH AS，UNION ALL 查詢

一、查詢Id爲1全部的下級

WITH T
AS( 
    SELECT * FROM table1 WHERE Id=1
    UNION ALL 
    SELECT a.*  FROM table1 a INNER JOIN T ON a.ParentId=T.Id  
) 
SELECT * FROM T

二、查詢Id爲88全部的上級

WITH T
AS( 
    SELECT * FROM table1 WHERE Id=88
    UNION ALL 
    SELECT a.*  
    FROM table1 a INNER JOIN T ON a.Id=T.ParentId  
) 
SELECT * FROM T