From: James Herdman <james.herdman@...>
Date: 2008-06-05T01:31:30+09:00
Subject: Re: Commercial Calendar Calculations

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Oh, I see!  So if you wanted to get the Date object corresponding to a row
you'd just dump those values into Date.civil.  Smart!

I'm curious about your occurrences table.  I think I understand this to be
one-time-only events.  Is that correct?

James

On Wed, Jun 4, 2008 at 11:07 AM, Donald Ball <donald.ball@gmail.com> wrote:

> On Tue, Jun 3, 2008 at 7:59 PM, James Herdman <james.herdman@gmail.com>
> wrote:
> > Donald,
> > I'm definitely interested in hearing about the details.  I'll be having
> to
> > deal with an RDBMS as well.
>
> Sure thing, I'll describe briefly here and you can feel free to email
> me if you have further questions. My data model included a table of
> events, a table of occurrences for events on specific dates, and a
> table of recurrences for events that recur. The recurrences table has
> columns for event id, weekday, monthweek, and monthday; an event
> occurring on all Mondays would have 1 for weekday and null for the
> others, while an event occurring on the last Friday of a month would
> have 5 for the weekday and -1 for the monthweek. I created a view
> joining these data (events, occurrences, recurrences) against a table
> of dates, excluding holidays, and end up with a virtual table
> consisting of a row for every valid event-date pair.
>
> Given that the date functions in SQL aren't standardized, I'd thought
> this would have been practically difficult to bundle up as a rails
> plugin, but it now occurs to me that I could store the date parts
> (e.g. weekday) in the table of dates, eliminating the need for any
> date functions in the database. I may give that a whirl this weekend.
>
> - donald
>
>

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