Re: [SQLObject] Composed Primary key

[Brad B. <br...@bb...>]

On Thu, Jul 17, 2003 at 01:41:02PM -0500, Ian Bicking wrote:
> On Thu, 2003-07-17 at 11:09, Fran?ois Girault wrote:
> > Hi all,
> > 
> > here's another feature I need for my project : I have several tables
> > whose primary key is composed of two or three columns.
> 
> Well, if there's going to be composite keys, that might as well be
> generalized to all the columns (i.e., any attribute could be a composite
> of several columns).

What's the use case for this?

Composition seems fairly specific to primary key definitions; I don't
see it useful as a general purpose thing that belongs in SQLObject
column definition semantics. I would have thought it preferable to
define columns as normal, and then create another property to abstract
them.

e.g. (slightly contrived, and totally untested)

class Date(SQLObject):

    day = IntCol()
    month = IntCol()
    year = IntCol()

    def get_date(self):
        return "%d/%02d/%02d" % (self.year, self.month, self.day)

    def set_date(self, value):
        self.year, self.month, self.day = [int(x) for x in value.split("-")]
        
    date = property(get_date, set_date)

--
Brad Bollenbach
BBnet.ca