Website navigation hierarchy with SQL Server 2005

[Brian]

Hi

I'm trying to convert some verbose SQL Server 2000 T-SQL code that uses
lots temp tables and the like into a SQL Server 2005 only version,
possibly using CTE.

What I want to achieve is a menu like that on

http://www.cancerline.com/cancerlinehcp/9898_9801_6_3_3.aspx

Notice how you have the top level menu items, and then child nodes
expanded down to the low level page that link sends you to.

Table sql:

CREATE TABLE [dbo].[NavigationNode](
[NodeId] [int] primary key nonclustered,
[Text] [nvarchar](150) COLLATE SQL_Latin1_Gene ral_CP1_CI_AS NULL,
[AlternativeText] [nvarchar](250) COLLATE SQL_Latin1_Gene ral_CP1_CI_AS
NULL,
[Level] [int] NULL,
[ParentNodeId] [int] constraint fk_parent_navno de
foreign key references [NavigationNode] ([NodeId])
)

Table data:

1 Home NULL 1 NULL
2 Solutions NULL 1 1
3 Solutions child1 NULL 2 2
4 Solutions child2 NULL 2 2
5 Contact NULL 1 1
6 solutions child1 child1 NULL 3 3
7 solutions child1 child2 NULL 3 3
8 solutions child1 child3 NULL 3 3
9 solutions child1 child4 NULL 3 3
10 contact child1 NULL 2 5

I have started to write some code with the common table expression
syntax:

declare @root int;
set @root = 2;

WITH Nav([NodeId],[ParentNodeId], [Text], [Level]) AS
(
SELECT [NodeId], [ParentNodeId], [Text], [Level]
FROM [dbo].[NavigationNode]
WHERE [ParentNodeId] = @root

UNION ALL

SELECT n1.[NodeId], n1.[ParentNodeId], n1.[Text], n1.[Level]
FROM [dbo].[NavigationNode] n1
INNER JOIN Nav n2
ON n1.[ParentNodeId] = n2.[NodeId]

)
SELECT *
FROM Nav

Which returns:

3 2 Solutions child1 2
4 2 Solutions child2 2
6 3 solutions child1 child1 3
7 3 solutions child1 child2 3
8 3 solutions child1 child3 3
9 3 solutions child1 child4 3

However I would prefer to the childnode, and then get parents of that
child recursively. Doing that would leave me with a result set that
could add the top level menu items to and have all the data required.
Any help is greatly appreciated.

-Brian

[Erland Sommarskog]

Re: Website navigation hierarchy with SQL Server 2005

Brian (dotnetdev@gmai l.com) writes:[color=blue]
> However I would prefer to the childnode, and then get parents of that
> child recursively. Doing that would leave me with a result set that
> could add the top level menu items to and have all the data required.
> Any help is greatly appreciated.[/color]

I couldn't really understand how you wanted the output. However, judging
from the link you posted, you might be looking for something like:

declare @root int;
set @root = 6;


WITH Nav([NodeId],[ParentNodeId], [Text], [Level]) AS
(
SELECT n2.NodeId, n2.ParentNodeId , n2.Text, n2.[Level]
FROM [dbo].[NavigationNode] n1
JOIN NavigationNode n2 ON n1.ParentNodeId = n2.ParentNodeId
WHERE n1.NodeId = @root

UNION ALL

SELECT n2.NodeId, n2.ParentNodeId , n2.Text, n2.[Level]
FROM [dbo].[NavigationNode] n1
JOIN NavigationNode n2 ON n1.ParentNodeId = n2.ParentNodeId
INNER JOIN Nav n3 ON n3.[ParentNodeId] = n1.[NodeId]

)
SELECT DISTINCT *
FROM Nav
UNION ALL
SELECT NodeId, ParentNodeId, Text, [Level]
FROM NavigationNode
WHERE ParentNodeId IS NULL


Maybe not the most elegant, but the hour is late here...



--
Erland Sommarskog, SQL Server MVP, esquel@sommarsk og.se

Books Online for SQL Server 2005 at

http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx

Books Online for SQL Server 2000 at

http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx