sql循环（WITH AS短语也叫做子查询部分）

--表结构  SELECT id,position,Parentid FROM op_client_sales_structure 

WITH TEST_CTE
 AS
 (
 SELECT id,position,Parentid,Cast(Parentid AS NVARCHAR()) AS PATH
 FROM op_client_sales_structure team
 WHERE Parentid !=-
 UNION ALL
 SELECT a.id,a.position,a.Parentid,
 CTE.PATH+','+Cast(a.Parentid AS NVARCHAR()) AS PATH
 FROM op_client_sales_structure a
 INNER JOIN TEST_CTE CTE ON a.id=CTE.Parentid
)
 SELECT * FROM TEST_CTE  WHERE Parentid=(SELECT id FROM op_client_sales_structure WHERE Parentid=-)
--限制递归次数
 OPTION(MAXRECURSION )