Question

我想检索一个id的parentid，如果那个parentid让父母再次检索它，依此类推。层次结构表的种类。

id----parentid
1-----1
5-----1
47894--5
47897--47894

是sql server的新手并尝试了一些查询，如：

with name_tree as 
(
   select id, parentid
   from Users
   where id = 47897 -- this is the starting point you want in your recursion
   union all
   select c.id, c.parentid
   from users c
   join name_tree p on p.id = c.parentid  -- this is the recursion
) 
select *
from name_tree;

它只给我一排。我还想将这些记录插入临时表变量中。我怎样才能做到这一点。提前致谢。很抱歉问这个简单的问题（虽然不是我）

Answer 1

尝试这样做以获得孩子的所有父母

;with name_tree as 
(
   select id, parentid
   from Users
   where id = 47897 -- this is the starting point you want in your recursion
   union all
   select C.id, C.parentid
   from Users c
   join name_tree p on C.id = P.parentid  -- this is the recursion
   -- Since your parent id is not NULL the recursion will happen continously.
   -- For that we apply the condition C.id<>C.parentid 
    AND C.id<>C.parentid 
) 
-- Here you can insert directly to a temp table without CREATE TABLE synthax
select *
INTO #TEMP
from name_tree
OPTION (MAXRECURSION 0)

SELECT * FROM #TEMP

Click here查看结果

编辑：

如果要插入表变量，可以执行以下操作：

-- Declare table varialbe
Declare @TABLEVAR table (id int ,parentid int)


;with name_tree as 
(
   select id, parentid
   from #Users
   where id = 47897 -- this is the starting point you want in your recursion
   union all
   select C.id, C.parentid
   from #Users c
   join name_tree p on C.id = P.parentid  -- this is the recursion
   -- Since your parent id is not NULL the recursion will happen continously.
   -- For that we apply the condition C.id<>C.parentid 
    AND C.id<>C.parentid 
) 
-- Here you can insert directly to table variable
INSERT INTO @TABLEVAR
select *
from name_tree
OPTION (MAXRECURSION 0)

SELECT * FROM @TABLEVAR

Click here查看结果

Answer 2

您的查询正在进行递归，但方向相反。因此，如果您将起点更改为：

where id = 1

然后您将拥有用户1及其所有后继者

Answer 3

你没有提到所需的输出和输入。但是你可以这样试试，

Declare @t table (id int ,parentid int)
insert into @t
select 1,1 union all
select 5,1 union all
select 47894,5 union all
select 47897,47894 

;With CTE as
(
select * from @t where id=1
union all
Select a.* from @t a inner join cte b
 on b.id=a.parentid and
a.id<>b.id
)
select * from cte

让所有父母为孩子

3 个答案: