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How do I create a tree diagram from non-recursive data in SQL Server 2008 R2

I have a question and it's really frustrating and I think it's simply that I don't completely understand how to set up hierarchies in SQL Server 2008 R2. I have looked at recursive CTEs, the hierarchy data type and XML and really can't get my head around how I can do what I need to do.
 
I need to be able to create a tree structure from data in an SQL Server 2008 R2 database  which will be sent as HTML in an auto-generated email which would be similar to the following:
 
Author
-- Year book written
------ Publisher
----------- Genre
 
So that for each author I can provide a tree of all their information so they could see what books they have written in a given time period e.g.
 
John Doe
-- 1999
------ Apress
----------- Historical
----------- Science Fiction
------ Wiley
----------- Classical
----------- Historical
----------- Science Fiction
-- 2009
------ Bloomsbury
----------- Classical
----------- Romance
----------- Science Fiction
------ Wiley
----------- Classical
 
I actually need to generate HTML (I added "ul" and "li" as part of the select statement using FOR XML PATH, which sort of added the tags correctly although not quite according to XHTML standards, but I can tweak that once the hierarchy itself is sorted) to present the information in an email and had used FOR XML PATH but that didn't work exactly as I needed but I think part of the problem was that I really didn't understand how to generate the hierarchy in the first place. I can see how to do it with recursive data but my data is not recursive, although I don't know if I can apply the same principles even if the data is not recursive.
 
I get the information from a temporary variable I created that has a row for each full hierarchy - I used a temporary variable so that the code looks nice and is easy to understand and strips out any data I don't need.  The table variable is re-used in a couple of places in the stored procedure, hence part of the reason for using a table variable.  These are examples of the rows with the columns seperated by dashes below:
 
John Doe - 1999 - Apress - Historical
John Doe - 1999 - Apress - Science Fiction
John Doe - 1999 - Wiley - Classical
John Doe - 1999 - Wiley - Historical
John Doe - 1999 - Wiley - Science Fiction
John Doe - 2009 - Bloomsbury - Classical
John Doe - 2009 - Bloomsbury - Romance
John Doe - 2009 - Bloomsbury - Science Fiction
John Doe - 2009 - Wiley - Classical
 
This may not be the best way to capture the data for generating the email hierarchy but it gave me a list of all the various possibilities, which is why I started there and if I used excel pivot tables the data in this column format was able to give me exactly what I needed.  But I don't want to use excel, I want the emails to auto generate.

Any insight is gratefully received.

Thank you.
0
lilycollins
Asked:
lilycollins
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1 Solution
 
wdosanjosCommented:
Here is what I got:

select Author.Author as [is],
       [Year].[Year] as [is], 
       Publisher.Publisher as [is], 
       Genre.Genre as [is]
  from YourTable Genre
  inner join (select distinct Author from YourTable) Author on Author.Author = Genre.Author
  inner join (select distinct Author, [Year] from YourTable) [Year] on [Year].Author = Genre.Author and [Year].[Year] = Genre.[Year]
  inner join (select distinct Publisher from YourTable) Publisher on Publisher.Publisher = Genre.Publisher
FOR XML AUTO

Open in new window


Which generates the following XML:

<Author is="John Doe">
	<Year is="1999">
		<Publisher is="Apress">
			<Genre is="Historical"/>
			<Genre is="Science Fiction"/>
		</Publisher>
		<Publisher is="Wiley">
			<Genre is="Classical"/>
			<Genre is="Historical"/>
			<Genre is="Science Fiction"/>
		</Publisher>
	</Year>
	<Year is="2009">
		<Publisher is="Bloomsbury">
			<Genre is="Classical"/>
			<Genre is="Romance"/>
			<Genre is="Science Fiction"/>
		</Publisher>
		<Publisher is="Wiley">
			<Genre is="Classical"/>
		</Publisher>
	</Year>
</Author>

Open in new window


It's not XHTML, but I think you can get there through simple string replaces.
0
 
lilycollinsAuthor Commented:
Thank you very much for your response, I completely agree that the conversion to XHTML is a straightforward replace etc.

I will try your solution and let you know how it works out.

Thank you.
0
 
lilycollinsAuthor Commented:
Very helpful and clearly documented response.
0
 
lilycollinsAuthor Commented:
Dear wdosanjos,

Thank you for your help.  I had been pulling my hair out over this and as per usual it's a pretty simply solution once you have seen it, smile.

It works beautifully.

Thank you.
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