SQL Server 父子迭代查询语句，树状查询

这个也有用：

-- Get childs by parent id
WITH Tree
AS
(
SELECT Id,ParentId FROM dbo.Node P WHERE P.Id = 21 -- parent id
UNION ALL
SELECT C.Id,C.ParentId FROM dbo.Node C
INNER JOIN Tree T ON C.ParentId = T.Id
)
SELECT * FROM Tree

-- Get parents by child id
WITH Tree
AS
(
SELECT Id,ParentId FROM dbo.Node C WHERE C.Id = 57 -- child id
UNION ALL
SELECT P.Id,P.ParentId FROM dbo.Node P
INNER JOIN Tree T ON P.Id = T.ParentId
)
SELECT * FROM Tree

原文转自 https://www.cnblogs.com/i0air/archive/2013/01/14/2859635.html