SQL CTE递归

WITH cte_name
AS
(
--Anchor member is defined
select PCY_Name,PCY_ID,PCY_Parent,PCY_Code,PCY_Status from PB_Code_MaterType where PCY_ID=''
UNION ALL
--Recursive member is defined referencing cte_name
select a.PCY_Name,a.PCY_ID,a.PCY_Parent,
a.PCY_Code,a.PCY_Status from PB_Code_MaterType a
inner join cte_name c on a.PCY_Parent=c.PCY_ID
)
-- Statement using the CTE
SELECT *,(select PCY_Name from PB_Code_MaterType where PCY_ID=cte_name.PCY_Parent)PCY_ParentTxt
FROM cte_name

https://blog.csdn.net/3150379/article/details/54865603