Would this be the best approach:
todays_ids = set(used_ad_ids)
unseen_ads_query = self.db(~self.db.ads.id.belongs(todays_ids))
unseen_ads_query = unseen_ads_query(self.db.ads.points >= 0)
unseen_ads_query = unseen_ads_query(self.db.ads.viewable == True)
unseen_ads_query = unseen_ads_query(self.db.ads.accepted == True)
*unseen_ads = unseen_ads_query.select(orderby='<random>',
limitby=(0,5))*
On Fri, Jan 20, 2012 at 3:34 PM, Bruce Wade <[email protected]> wrote:
> Hi,
>
> I have selected a list of objects from the database, which is working. Now
> I would like to select 5 random rows from the list and ideally only hit the
> database once to get them 5 random rows.
>
> todays_ids = set(used_ad_ids)
> unseen_ads_query = self.db(~self.db.ads.id.belongs(todays_ids))
> unseen_ads_query = unseen_ads_query(self.db.ads.points >= 0)
> unseen_ads_query = unseen_ads_query(self.db.ads.viewable == True)
> unseen_ads_query = unseen_ads_query(self.db.ads.accepted == True)
> unseen_ads = unseen_ads_query.select()
>
> # now pull 5 random rows out of the returned rows, each time this
> method is called the random 5 should always be different from the last call.
> # Can this be done before the last select() statement and allow to
> use limit(5) so the database isn't hit so hard if there were 1,000,000
> results in the select() and I only need 5 random out of the 1,000,000
>
> return unseen_ads
>
> Also please let me know if their is a more efficient way to do the above
> query.
>
> --
> --
> Regards,
> Bruce Wade
> http://ca.linkedin.com/in/brucelwade
> http://www.wadecybertech.com
> http://www.warplydesigned.com
> http://www.fitnessfriendsfinder.com
>
--
--
Regards,
Bruce Wade
http://ca.linkedin.com/in/brucelwade
http://www.wadecybertech.com
http://www.warplydesigned.com
http://www.fitnessfriendsfinder.com
