Ok, I was about to stand my ground, however I now agree with you.
virtualfields is fine to me, as long as our DAL gets support for native SQL
aggregates (liek SUM, AVG, etc).
And when the DAL gets that, it leaves open the option to assign true aliases
that are tied into the SQL query.
aliases = {
'num_items': ['count', '*'],
'total_price': ['sum', 'item.price'],
'average_price': ['avg', 'item.price'],
}
db(db.invoice.id == request.vars.id_invoice).select(alias=aliases)
So i'm okay with virtualfields now :P
-Thadeus
On Tue, Oct 27, 2009 at 4:12 PM, mdipierro <mdipie...@cs.depaul.edu> wrote:
>
> No no. We are not doing that.
>
> The new virtualfields are compute by web2py, not by the database.
>
> Massimo
>
> On Oct 27, 3:55 pm, Thadeus Burgess <thade...@thadeusb.com> wrote:
> > Basically what we are doing is
> >
> > SELECT COUNT(*) AS "Number of Orders",
> > SUM(quantity)AS "Total Number of Items Purchased",
> > AVG(quantity)AS "Average Number of Items Purchased"
> >
> > FROM orders;
> >
> > What is the correct terminology for AS statement? Some research suggest
> > ALIAS is the most accurate term.
> >
> > I think we should use "alias" or "aliases"
> >
> > http://www.w3schools.com/sql/sql_alias.asp
> >
> > -Thadeus
> >
> > On Tue, Oct 27, 2009 at 3:31 PM, mdipierro <mdipie...@cs.depaul.edu>
> wrote:
> >
> > > I am going with "virtualfields"
> >
> > > On Oct 27, 3:19 pm, mdipierro <mdipie...@cs.depaul.edu> wrote:
> > > > we normally user expressions to refer to things like this
> >
> > > > db(query).update(field=db.table.field+1)
> >
> > > > How about interface?
> >
> > > > On Oct 27, 3:05 pm, Thadeus Burgess <thade...@thadeusb.com> wrote:
> >
> > > > > Not meta, too confusing with django stuff.
> >
> > > > > How about expression, makes much more sense. That is what it is
> > > actually
> > > > > referred to when talking about SQL. Access calls them expressions
> as
> > > well.
> >
> > > > > -Thadeus
> >
> > > > > On Tue, Oct 27, 2009 at 2:32 PM, mdipierro <
> mdipie...@cs.depaul.edu>
> > > wrote:
> >
> > > > > > should this thing be called meta? interface? extension?
> >
> > > > > > On Oct 27, 2:26 pm, mdipierro <mdipie...@cs.depaul.edu> wrote:
> > > > > > > Simple example:
> >
> > > > > > > db=DAL('sqlite://test')
> > > > > > > db.define_table('purchase',
> > > > > > > Field('item'),
> > > > > > > Field('unit_price','double'),
> > > > > > > Field('quantity','integer'))
> > > > > > > db.purchase.insert(item='Box',unit_price=15,quantity=3)
> > > > > > > rows=db().select(db.purchase.ALL)
> >
> > > > > > > class purchase_meta:
> > > > > > > _tablename='purchase'
> > > > > > > def __init__(self,tax):
> > > > > > > self.tax=tax
> > > > > > > def revenues(self):
> > > > > > > return
> > > > > > > self.purchase.unit_price*self.purchase.quantity*self.tax
> >
> > > > > > > rows.meta=purchase_meta(1.07)
> >
> > > > > > > for row in rows:
> > > > > > > print row.item,
> > > > > > > row.unit_price,'*',row.quantity,'*',row.tax,'=',row.revenues
> >
> > > > > > > More complex example:
> >
> > > > > > > db.define_table('a',Field('n','integer'))
> > > > > > > db.define_table('b',Field('n','integer'),Field('a',db.a))
> > > > > > > id = db.a.insert(n=4)
> > > > > > > for i in range(3,5): db.b.insert(n=i,a=id)
> > > > > > > rows=db(db.b.a==db.a.id).select() ### join
> >
> > > > > > > class products:
> > > > > > > _tablename='c'
> > > > > > > def n(self): return self.a.n*self.b.n
> >
> > > > > > > rows.meta=products()
> > > > > > > for row in rows:
> > > > > > > print row.a.n,'*',row.b.n,'=' row.c.n
> >
> > > > > > > Any suggestions on improving the syntax? Django can do the same
> but
> > > > > > > only at the level of the individual table. web2py can now to it
> for
> > > > > > > joins!
> >
>
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