2010-08-17 89 views
1

我有一个在SQL Server相关的性能的一个大查询2005年我在SQL Server相关的性能的一个大查询2005

我有这样

id parentId 
1 null 
2 1 
3 1 
4 2 
5 4 
6 3 

我想为了使数据通过与parentId的下线和id明智 像

id Order 
1 1 
2 2 
4 3 
5 4 
3 5 
4 6 

我不想使用循环,因为循环是建立高,如果行数的问题记录。 请给我简单的方法来做到这一点,并伤害到性能。

更新, 请运行下面

 

create table [mytable] ( [id] int, [parentId] int ) GO

INSERT INTO [mytable] ([id],[parentId])VALUES(1,NULL) INSERT INTO [mytable] ([id],[parentId])VALUES(2,6) INSERT INTO [mytable] ([id],[parentId])VALUES(4,9) INSERT INTO [mytable] ([id],[parentId])VALUES(5,4) INSERT INTO [mytable] ([id],[parentId])VALUES(6,13) INSERT INTO [mytable] ([id],[parentId])VALUES(7,13) INSERT INTO [mytable] ([id],[parentId])VALUES(8,5) INSERT INTO [mytable] ([id],[parentId])VALUES(9,1) INSERT INTO [mytable] ([id],[parentId])VALUES(13,1) GO

; WITH q AS ( SELECT id, parentId, CAST(id AS VARCHAR(MAX)) + '/' AS path FROM mytable WHERE parentId IS NULL UNION ALL SELECT t.id, t.parentId, q.path + CAST(t.id AS VARCHAR(MAX)) + '/' FROM q JOIN mytable t ON t.parentId = q.id ) SELECT *, ROW_NUMBER() OVER (ORDER BY path) AS rn FROM q ORDER BY path GO

The result of this query ID ParentId Path rn 1 NULL 1/ 1 13 1 1/13/ 2 6 13 1/13/6/ 3 2 6 1/13/6/2/ 4 7 13 1/13/7/ 5 9 1 1/9/ 6 4 9 1/9/4/ 7 5 4 1/9/4/5/ 8 8 5 1/9/4/5/8/ 9

的剧本,但我想从avove结果第1,那么1/9 then1/9/...然后1/13/RN然后将结果1/13/...。请给我解决方案。

我想导致像

 


ID ParentId Path  rn 
1 NULL 1/  1 
13 1 1/13/  6 
6 13 1/13/6/  7 
2 6 1/13/6/2/ 8 
7 13 1/13/7/  9 
9 1 1/9/   2 
4 9 1/9/4/  3 
5 4 1/9/4/5/  4 
8 5 1/9/4/5/8/ 5 

 

 


WITH q AS 
     ( 
     SELECT id, parentId, CAST(id AS VARCHAR(MAX)) AS path 
     FROM mytable 
     WHERE parentId IS NULL 
     UNION ALL 
     SELECT t.id, t.parentId, q.path + '/' + CAST(t.id AS VARCHAR(MAX)) 
     FROM q 
     JOIN mytable t 
     ON  t.parentId = q.id 
     ) 
SELECT *, ROW_NUMBER() OVER (ORDER BY path) AS rn 
FROM q 
ORDER BY 
     path 

 

在上面 有一个问题。 您正在使用路径顺序 的顺序,假设在记录如1/13和1/2的情况下,所以顺序依次为1/13和1/2,但我想要顺序1/2然后是1/13,因为2是小于13

+1

ORDER BY顺序,编号? – JonH 2010-08-17 14:52:19

+3

我认为您的预期结果存在拼写错误。如果最后的ID是6而不是4? – 2010-08-17 14:53:55

回答

3
WITH q AS 
     (
     SELECT id, parentId, CAST(id AS VARCHAR(MAX)) + '/' AS path 
     FROM mytable 
     WHERE parentId IS NULL 
     UNION ALL 
     SELECT t.id, t.parentId, q.path + CAST(t.id AS VARCHAR(MAX)) + '/' 
     FROM q 
     JOIN mytable t 
     ON  t.parentId = q.id 
     ) 
SELECT *, ROW_NUMBER() OVER (ORDER BY path) AS rn 
FROM q 
ORDER BY 
     path 
+1

你能解释一下我对你从哪里得到这个问题感到困惑吗? – msarchet 2010-08-17 14:57:26

+0

@msarchet:这是一个呈现为邻接列表的层次结构。 @op希望按照树形顺序查找每个条目的位置。 – Quassnoi 2010-08-17 15:03:12

+0

谢谢,它确实有效。 – Paresh 2010-08-17 15:06:14

0

我不能告诉你准确的数据库是什么样子,但这样的事情应该工作

Select id, [Order] From Table1 Order By Order, id 
0
select id, parentid as order from table 
order by coalesce(parentid, 9999), id