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Re: Summing & Grouping in a Hierarchical Structure - Mailing list pgsql-sql

From Don Parris
Subject Re: Summing & Grouping in a Hierarchical Structure
Date
Msg-id CAJ-7yomqNwXC2WqE6u44c6rMdfa_-3Hr1EXpTFX_Nmn346tqvQ@mail.gmail.com
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In response to Re: Summing & Grouping in a Hierarchical Structure  ("Alexander Gataric" <gataric@usa.net>)
Responses Re: Summing & Grouping in a Hierarchical Structure
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Hi Alexander,

I appreciate you taking time to reply to my post.  I like the idea of the WITH RECURSIVE query, but...  The two examples in the link you offered are not so helpful to me.  For example, the initial WITH query shown uses a single table, and I wander how that might apply in my case, where the relevant information is actually found in two tables, one of them a recursive table.

The second example, which applies the WITH RECURSIVE clause, is even less so.  I wonder if there is a good tutorial somewhere on this that shows some other examples?  That might help me catch on a little better.  I'll search for that today.


On Thu, Feb 14, 2013 at 11:30 PM, Alexander Gataric <gataric@usa.net> wrote:

I would try a recursive query to determine the category structure and aggregate as you go. I had a similar problem with a hierarchical structure for an organization structure. Another thing you might try is to create a separate CTE for each category and then aggregate the individual CTEs.

 

 

From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org] On Behalf Of Don Parris
Sent: Thursday, February 14, 2013 7:58 PM
To: pgsql-sql@postgresql.org
Subject: [SQL] Summing & Grouping in a Hierarchical Structure

 

Hi all,

I posted to this list some time ago about working with a hierarchical category structure.   I had great difficulty with my problem and gave up for a time.  I recently returned to it and resolved a big part of it.  I have one step left to go, but at least I have solved this part.

Here is the original thread (or one of them):
http://www.postgresql.org/message-id/CAJ-7yonw4_qDCp-ZNYwEkR2jdLKeL8nfGc+-TLLSW=Rmo1VkbA@mail.gmail.com

 

Here is my recent blog post about how I managed to show my expenses summed and grouped by a mid-level category:
http://dcparris.net/2013/02/13/hierarchical-categories-rdbms/


Specifically, I wanted to sum and group expenses according to categories, not just at the bottom tier, but at higher tiers, so as to show more summarized information.  A CEO primarily wants to know the sum total for all the business units, yet have the ability to drill down to more detailed levels if something is unusually high or low.  In my case, I could see the details, but not the summary.  Well now I can summarize by what I refer to as the 2nd-level categories.

Anyway, I hope this helps someone, as I have come to appreciate - and I mean really appreciate - the challenge of working with hierarchical structures in a 2-dimensional RDBMS.  If anyone sees something I should explain better or in more depth, please let me know.

 

Regards,

Don

--
D.C. Parris, FMP, Linux+, ESL Certificate
Minister, Security/FM Coordinator, Free Software Advocate

GPG Key ID: F5E179BE




--
D.C. Parris, FMP, Linux+, ESL Certificate
Minister, Security/FM Coordinator, Free Software Advocate
GPG Key ID: F5E179BE

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