perfect, thanks cfh !
On Sun, Jul 17, 2011 at 10:45 PM, howesc <[email protected]> wrote:
> i see 2 options:
>
> db.define_table('tabletest', Field('yes', 'integer'), Field('no',
> 'integer'), Field('tot', 'integer', compute=lambda r:r.yes-r.no))
>
> will compute the value upon write and store it in the db, sort like any
> other field.
>
> or
>
> db.define_table('tabletest', Field('yes', 'integer'), Field('no',
> 'integer'))
>
> class vf():
> def tot(self):
> return self.tabletest.yes-self.tabletest.no
>
> db.tabletest.virtualfields.append(vf)
>
> will create a virtual field that is computed on read. to sort by the
> virtual field you can:
>
> db(db.tabletest.id>0).select().sort(lambda r: r.tot)
>
> hope that helps. (i did not test my code, just typed quickly, beware of
> typos)
>
> cfh
>
--
Sebastian E. Ovide
