Обсуждение: 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