Thread: GROUP by finish&&last day of month

Ok, if I want to get non-aggregat data in groups, I use order by. This 
group by seemed so logical though, but the fruit that u can't have, is
usually the most sweet.

New question, how to get the last day of month(order data by last day of
month). And to prevent chain letter from misunderstanding, no I don't
intend to look it up from calendar and then input it manually. 

A.

On Wed, 5 Jul 2000, Antti Linno wrote:

> New question, how to get the last day of month(order data by last day of
> month). 

I'm sorry but I don't understand how you could order something by a value
(last day of month).

you can only order things by a field (e.g. a date field) or fields, in
increasing or decreasing order. 

e.g.:

you can do:

SELECT id,eventdate FROM mytable ORDER BY eventdate DESC;

and not:

SELECT id,eventdate FROM mytable ORDER BY '2000-01-31' DESC; 

the latter one doesn't mean anything to me, nor to SQL I suppose.

bye,

Jerome ALET - alet@unice.fr - http://cortex.unice.fr/~jerome
Faculte de Medecine de Nice - http://noe.unice.fr - Tel: 04 93 37 76 30 
28 Avenue de Valombrose - 06107 NICE Cedex 2 - FRANCE

Not quite sure what you mean, but how about this:

select date_part('day', 'Jul 01 00:00:00 2000 PDT'::datetime-1);

You must specify Jul for June, i.e. always the following month.
You could get around that too, but since I don't know why you
need to do what you asked, I'll leave it at this.



Troy


>
> Ok, if I want to get non-aggregat data in groups, I use order by. This
> group by seemed so logical though, but the fruit that u can't have, is
> usually the most sweet.
>
> New question, how to get the last day of month(order data by last day of
> month). And to prevent chain letter from misunderstanding, no I don't
> intend to look it up from calendar and then input it manually.
>
> A.
>
>
>

Antti Linno wrote:

> Ok, if I want to get non-aggregat data in groups, I use order by. This
> group by seemed so logical though, but the fruit that u can't have, is
> usually the most sweet.
>
> New question, how to get the last day of month(order data by last day of
> month). And to prevent chain letter from misunderstanding, no I don't
> intend to look it up from calendar and then input it manually.
>
> A.

to get last day of month :
1) use date-trunc to truncate to first day of month
2) add one month
3) substract 1 day