Re: [SQL] fetch first rows of grouped data

2007-08-28 Thread hubert depesz lubaczewski
On Tue, Aug 28, 2007 at 08:00:42AM -0500, Michael Glaesemann wrote: > >you can try to use "distinct on". > I considered that as well, but couldn't think of a way to return more you're right and i was wrong. i simply missed the word "two" in original question. sorry. depesz -- quicksil1er: "po

Re: [SQL] fetch first rows of grouped data

2007-08-28 Thread Michael Glaesemann
On Aug 28, 2007, at 4:14 , hubert depesz lubaczewski wrote: On Mon, Aug 27, 2007 at 06:36:47PM +0200, Claudia Kosny wrote: Is there a way to do this with one query? I am using PostgreSQL 7.4. you can try to use "distinct on". I considered that as well, but couldn't think of a way to return

Re: [SQL] fetch first rows of grouped data

2007-08-28 Thread hubert depesz lubaczewski
On Mon, Aug 27, 2007 at 06:36:47PM +0200, Claudia Kosny wrote: > Is there a way to do this with one query? > I am using PostgreSQL 7.4. you can try to use "distinct on". depesz -- quicksil1er: "postgres is excellent, but like any DB it requires a highly paid DBA. here's my CV!" :) http://www.d

Re: [SQL] fetch first rows of grouped data

2007-08-27 Thread Michael Glaesemann
On Aug 27, 2007, at 13:12 , Michael Glaesemann wrote: select city, event, event_date, ( select count(event) from events i where i.city = o.city and i.event_date < o.event_date and event_date > current_date -- make sure they're future events This should be i.event

Re: [SQL] fetch first rows of grouped data

2007-08-27 Thread D'Arcy J.M. Cain
On Mon, 27 Aug 2007 13:34:09 -0400 Joel Richard <[EMAIL PROTECTED]> wrote: > That's what I thought at first, but this is not the case. She's > looking for the first two dates in -each- city in the table. I > initially thought that this could be accomplished with GROUP BY and > LIMIT, but GROU

Re: [SQL] fetch first rows of grouped data

2007-08-27 Thread Michael Glaesemann
[Please don't top post as it makes the discussion more difficult to follow.] On Aug 27, 2007, at 12:34 , Joel Richard wrote: On Aug 27, 2007, at 12:51 PM, D'Arcy J.M. Cain wrote: On Mon, 27 Aug 2007 18:36:47 +0200 Claudia Kosny <[EMAIL PROTECTED]> wrote: I have a list of events that take p

Re: [SQL] fetch first rows of grouped data

2007-08-27 Thread Joel Richard
That's what I thought at first, but this is not the case. She's looking for the first two dates in -each- city in the table. I initially thought that this could be accomplished with GROUP BY and LIMIT, but GROUP BY can only give you the first date for each city, not the first two dates for

Re: [SQL] fetch first rows of grouped data

2007-08-27 Thread D'Arcy J.M. Cain
On Mon, 27 Aug 2007 18:36:47 +0200 Claudia Kosny <[EMAIL PROTECTED]> wrote: > I have a list of events that take place in a certain city at a certain > date. Now I would like to have the first two (ordered by date) events > for each city. > > Is there a way to do this with one query? > I am using

[SQL] fetch first rows of grouped data

2007-08-27 Thread Claudia Kosny
Hi there I have a list of events that take place in a certain city at a certain date. Now I would like to have the first two (ordered by date) events for each city. Is there a way to do this with one query? I am using PostgreSQL 7.4. Thanks for any tips. Claudia -