> 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
>
