SqlServer查询父子关系

摘自：sqlserver查询父子级关系 - F风 - 博客园 (cnblogs.com)

自上向下的查询方法，查询出自身以及所有的子孙数据：

--自上往下搜索
;with maco as
(
select * from ty_Dictionary where id =21
union all 
select t.* from ty_Dictionary t,maco m where t.ParentID=m.ID
)
select distinct * from maco order by id desc

自下向上查询，查询出自身以及所有的直系祖先：

--自下往上搜索
;with maco as
(
select * from ty_Dictionary where id=23
union all 
select t.* from ty_Dictionary t,maco m where t.ID=m.ParentID
)
select * from maco order by id

删除自身以及所有的子孙数据：

;with maco as
(
select ID,ParentID from ty_Dictionary where ID=21
union all 
select t.ID,t.ParentID from ty_Dictionary t,maco m where t.ParentID=m.ID
)
delete from ty_Dictionary where ID in( select ID from maco group by ID)