From: Rainer Stengele <rainer.stengele@diplan.de>
To: pgsql-sql@postgresql.org
Subject: grouping subsets
Date: Thu, 22 Jul 2010 10:09:16 +0200
Message-ID: <i28ubc$ie9$1@dough.gmane.org> (raw)
Hi,
having a table similar to
| 1 | B | [2010-07-15 Do] |
| 1 | B | [2010-07-16 Fr] |
|---+---+-----------------|
| 2 | C | [2010-07-17 Sa] |
| 2 | C | [2010-07-18 So] |
|---+---+-----------------|
| 1 | B | [2010-07-19 Mo] |
| 1 | B | [2010-07-20 Di] |
| 1 | B | [2010-07-21 Mi] |
| 1 | B | [2010-07-22 Do] |
|---+---+-----------------|
| 3 | D | [2010-07-23 Fr] |
a simple group by gives me:
| 6 | B |
| 4 | C |
| 3 | D |
What I want to get is the values grouped by "subset", where a subset is a set of rows with identical column until the colum changes.
Is there a way to get
| 2 | B |
| 4 | C |
| 4 | B |
| 3 | D |
by SQL only?
- Rainer
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To: pgsql-sql@postgresql.org
Cc: rainer.stengele@diplan.de
Subject: Re: grouping subsets
In-Reply-To: <i28ubc$ie9$1@dough.gmane.org>
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