摘要: 下文通過遞迴的方式找出最頂級部門的方法分享，如下所示: 實驗環境:sql server 2008 R2

下文通過cte-with表示式實現遞迴，獲取一個公司的頂級部門，如下所示 例:部門表

create table [maomao365.com]
(keyId int ,parentId int,
deptName nvarchar(30))

insert into [maomao365.com]
(keyId,parentId,deptName)
values
(1,0,'總經辦'),
(2,0,'IT中心'),
(10,1,'銷售部'),
(11,1,'售後部
 
'),
(111,11,'售後1'),
(1111,111,'售後1_1'),
(12,1,'市場部'),
(21,2,'運維部'),
(22,2,'開發部')

---例1:獲取 售後部keyId=1111所在的頂級部門
;
with testA( [keyId], [parentid],deptName)
as
(
select keyId, parentid,deptName
from [maomao365.com]
where keyId = 1111
union all
select a.keyId, a.parentid,a.deptName
from
 
 [maomao365.com] a
inner join testA on a.[keyId] = testA.[parentId]  --遞迴
)

select * from testA where parentId=0;


go

truncate table [maomao365.com]
drop  table [maomao365.com]