无限层级结构的table1表，Id（主键）,ParentId（父级id）查询某个Id的所有下级或所有上级，使用WITH AS，UNION ALL 查询
1、查询Id为1所有的下级
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
2、查询Id为88所有的上级
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
