Question

如何查找max类型列的hierarchyid？

例如：

name  | user_hierarchyid
-------------------------
Craig | /
Steve | /1/
John  | /1/1/
Matt  | /1/1/1/
Sam   | /2/
Chris | /2/2/

我尝试使用max(user_hierarchyid)，但它会返回/2/2/，但我希望层次结构最多，即/1/1/1/

先谢谢。

Answer 1

您可以使用GetLevel()获取关卡，TOP 1 WITH TIES获取＆＃34; max＆＃34;（最深）值：

SELECT TOP 1 WITH TIES *
FROM mytable
ORDER BY user_hierarchyid.GetLevel() DESC;

的 LiveDemo

输出：

╔══════╦══════════════════╗ ║ name ║ user_hierarchyid ║ ╠══════╬══════════════════╣ ║ Matt ║ /1/1/1/ ║ ╚══════╩══════════════════╝

或者使用RANK()：

SELECT * FROM (SELECT *, RANK() OVER(ORDER BY user_hierarchyid.GetLevel() DESC) AS rnk FROM mytable) AS s WHERE rnk = 1;

的 LiveDemo2

Answer 2

你可以做类似下面的事情

with cte
as
(
select name,user_hier_id,replace(user_hierarchyid,'/','') as rplcd
from table
)
select max(rplcd) from cte

Answer 3

;WITH cte AS (
SELECT name, CAST(user_hierarchyid as hierarchyid) as user_hierarchyid
FROM (VALUES
('Craig', '/'),
('Steve', '/1/'),
('John', '/1/1/'),
('Matt', '/1/1/1/'),
('Sam', '/2/'),
('Chris', '/2/2/')
) as t(name, user_hierarchyid)
)

SELECT TOP 1
        name,
        CAST(user_hierarchyid as nvarchar(20)) as user_hierarchyid
FROM (
    SELECT  *,
            user_hierarchyid.GetAncestor(CASE WHEN user_hierarchyid.GetLevel() > 0 THEN user_hierarchyid.GetLevel()-1 ELSE user_hierarchyid.GetLevel() END ) as ga,
            user_hierarchyid.GetLevel() as gl
    FROM cte
    ) as t
ORDER BY Rank() OVER (PARTITION BY ga ORDER BY gl,user_hierarchyid ) desc, ga DESC

输出：

name  user_hierarchyid
----- -----------------
Matt  /1/1/1/

(1 row(s) affected)

如果您添加行('Dave', '/1/1/2/'),，则输出将为Dave /1/1/2/

如果您添加行('Tony', '/2/2/1/'),，则输出将为Dave /1/1/2/

如果您添加行('Ann', '/2/2/2/'),，则输出将为Ann /2/2/2/

如果您添加行('Vic', '/1/1/1/1/'),，则输出将为Vic /1/1/1/1/

在SQL Server中查找Max Hierarchyid

3 个答案: