Hi I think that you should take a look at http://www.xaprb.com/blog/2006/12/07/how-to-select-the-firstleastmax-row-per-group-in-sql/
It looks like there are some sql examples for your problem Br. Mr. Electronic On 6 Nov., 12:15, Ruiwen Chua <[email protected]> wrote: > Hi all, > > I have a message table defined as such: > > db.define_table('message', > Field('recipient', 'integer', writable=False, required=True), > Field('entity', 'string', length=256, required=True, notnull=True), > Field('text', 'string', length=2048, required=True, notnull=True), > Field('created', 'datetime', default=request.now, writable=False, > notnull=True), > format='%(msg_type)s by %(sender)s: %(text)s on %(created)s' > ) > > I would like to pull a list of most recent messages for a particular > recipient for all entities. > > However, on each poll, there might have been multiple messages for any > particular entity since the last poll. > > Eg. > > recipient entity > text created > 8 answer-42-feedback Where are the flies going shoo? > 2010-10-30 > 19:08:02 > 8 answer-42-feedback This is feedback > 2010-10-31 18:32:00 > 8 answer-42-feedback what the hell? > 2010-11-05 21:59:56 > 8 answer-43-feedback this is a test > 2010-10-29 18:57:15 > 8 answer-45-feedback Green? > 2010-10-31 02:24:03 > > For the above result set, notice that the entity answer-42-feedback > has 3 records, each with a differing timestamp. I'd like to only get > the one with the timestamp 2010-11-05 21:59:56. The records for > answer-43-feedback and answer-45-feedback are fine. > > What would be the best way to retrieve the messages required? > > Cheers > Ruiwen
