From: Andrei Bintintan <klodoma@ar-sd.net>
To: cristivoinicaru <cristivoinicaru@dmhi.ct.ro>
To: pgsql-sql@postgresql.org
Subject: Re: sql
Date: Mon, 25 Oct 2004 13:04:46 +0300
Message-ID: <003001c4ba7a$0fbb3500$0b00a8c0@forge> (raw)
References: <013901c4ba6a$8771d320$7202a8c0@aaa>
> 2)if two ore more record have the same value of the maxim value of the
"ora"
> to select oly one of them
At this point you really have to decide which criteria you use for this
deciding.
I strongly suggest to use a uniqe ID for each row in the table(in your case
it is important):
CREATE TABLE "temp50" (
id serial primary key,
"gc" character varying(36),
"co" character varying(7),
"data" date,
"ora" smallint
);
Your selection can be made in many ways, but you have to decide the second
criteria.
One more thing:
Your table datas are:
1 >> 5003707G9G9419 22012BB 10-14-2004 82
2 >> 5003707G9G9419 22012BC 10-14-2004 44
3 >> 5003707G9G9419 22022BB 10-14-2004 82
4 >> 5003707G9G9420 22022BC 10-18-2004 49
The rows no 1 and 3 are "redundant" data's(they are the same). Do you really
want this???
Best regards,
Andy.
----- Original Message -----
From: "cristivoinicaru" <cristivoinicaru@dmhi.ct.ro>
To: <pgsql-sql@postgresql.org>
Sent: Monday, October 25, 2004 11:13 AM
Subject: [SQL] sql
> I have a postgres table like this:
>
> CREATE TABLE "temp50" (
> "gc" character varying(36),
> "co" character varying(7),
> "data" date,
> "ora" smallint
>
> );
>
> It contains the following records:
>
> 5003707G9G9419 22012BB 10-14-2004 82
> 5003707G9G9419 22012BC 10-14-2004 44
> 5003707G9G9419 22022BB 10-14-2004 82
> 5003707G9G9420 22022BC 10-18-2004 49
>
> I'd like the result of the sql interogation to be like this:
>
> 5003707G9G9419 22012BB 10-14-2004 82
> 5003707G9G9420 22022BC 10-18-2004 49
>
>
> Explanations:
> I want like sql interogation to select only one record from each "gc"
group
> record (who has the same code "gc" (that means that the "gc" field will be
> unique key)) with the following two condition:
> 1)from each "gc" group of records to select the record who has the value
of
> "ora" field maxim.
> 2)if two ore more record have the same value of the maxim value of the
"ora"
> to select oly one of them
>
> Thanks!
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 8: explain analyze is your friend
>
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: klodoma@ar-sd.net, cristivoinicaru@dmhi.ct.ro
Subject: Re: sql
In-Reply-To: <003001c4ba7a$0fbb3500$0b00a8c0@forge>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox