From: Florent THOMAS <mailinglist@tdeo.fr>
To: postgesql general <pgsql-general@postgresql.org>
Cc: Neil Stlyz <neilstylz@yahoo.com>
Subject: Re: combine SQL SELECT statements into one
Date: Mon, 01 Feb 2010 09:35:24 +0100
Message-ID: <1265013324.23250.21.camel@Dell_Inspiron> (raw)
In-Reply-To: <995516.81823.qm@web113717.mail.gq1.yahoo.com>
References: <995516.81823.qm@web113717.mail.gq1.yahoo.com>
Hi,
If I were you, I worked like this.
First make a union of those three query
Then make a crosstab :
http://www.postgresonline.com/journal/index.php?/archives/14-CrossTab-Queries-in-PostgreSQL-using-ta...
documented here :
http://www.postgresql.org/docs/8.4/interactive/tablefunc.html
Le dimanche 31 janvier 2010 à 23:36 -0800, Neil Stlyz a écrit :
> Good Evening, Good Morning Wherever you are whenever you may be
> reading this.
>
> I am new to this email group and have some good experience with SQL
> and PostgreSQL database.
>
>
> I am currently working on a PHP / PostgreSQL project and I came upon
> something I could not figure out in SQL. I was wondering if anyone
> here could take a look and perhaps offer some guidance or assistance
> in helping me write this SQL query.
>
> Please Consider the following information:
> -------------------------------------------
>
> I have a postgresql table called 'inventory' that includes two fields:
> 'model' which is a character varying field and 'modified' which is a
> timestamp field.
>
> So the table inventory looks something like this:
>
>
> model modified
> ------------- ----------
> I778288176 2010-02-01 08:27:00
> I778288176 2010-01-31 11:23:00
> I778288176 2010-01-29 10:46:00
> JKLM112345 2010-02-01 08:25:00
> JKLM112345 2010-01-31 09:52:00
> JKLM112345 2010-01-28 09:44:00
> X22TUNM765 2010-01-17 10:13:00
> V8893456T6 2010-01-01 09:17:00
>
>
>
> Now with the table, fields and data in mind look at the following
> three queries:
>
>
>
> SELECT COUNT(distinct model) FROM inventory WHERE modified >=
> '2010-02-01';
> SELECT COUNT(distinct model) FROM inventory WHERE modified >=
> '2010-01-20';
> SELECT COUNT(distinct model) FROM inventory WHERE modified >=
> '2010-01-01';
>
>
>
> All three of the above queries work and provide results. However, I
> want to combine the three into one SQL Statement that hits the
> database one time. How can I do this in one SQL Statement? Is it
> possible with sub select?
>
>
>
> Here is what result I am looking for from one SELECT statement using
> the data example from above:
>
>
>
> count1 | count2 | count3
> -------------------------------
> 2 2 4
>
>
> Can this be done with ONE SQL STATEMENT? touching the database only
> ONE time?
>
> Please let me know.
>
>
>
> Thanx> :)
> NEiL
>
>
>
>
>
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To: pgsql-sql@postgresql.org
Cc: mailinglist@tdeo.fr, pgsql-general@postgresql.org, neilstylz@yahoo.com
Subject: Re: combine SQL SELECT statements into one
In-Reply-To: <1265013324.23250.21.camel@Dell_Inspiron>
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