Re: How to model Recurring events?

Is there any decoder availabe to decode an event in crontab syntax? somthing like a shell command?

thanks in advance
Michael

"Thomas Muller" <ttm_at_online.no> schrieb im Newsbeitrag news:9gg463$dol$1_at_news6.svr.pol.co.uk...
> Hi Satish,
>
> I've had similar problems before, and I find that the Unix crontab
> representation works very well. If you're not familiar with the
 crontab
> pattern, here is a short explanation
>
> A crontab consists of five fields each specifying an integer pattern
 as
> follows:
> * minute (0-59)
> * hour (0-23)
> * day of the month (1-31)
> * month of the year (1-12)
> * day of the week (0-6 with 0=Sunday)
>
> Each of these patterns may be either an asterisk (meaning all legal
 values)
> or a list of elements separated by commas. An element is either a
 number or
> two numbers separated by a minus sign (meaning an inclusive range).
 Note
> that the specification of days may be made by two fields (day of the
 month
> and day of the week). Both are adhered to if specified as a list of
> elements.
>
> I've added a couple of fields: timezone (the timzone the crontab
 operate
> within), and valid timeset (the timeset the crontab is valid).
>
> Actually the Crontab is a class that implements the more general
 TimeSet
> interface which basically is a set of explicit moments and/or periods
 of
> time.
>
> The Crontab leaves you with complete flexibility for modelling
 recurring
> events.
>
> Now have do you store this in a relational database? Well, you could
 just
> keep is as a text value in a column relevant for the events. In order
 to
> speed up queries you would definately have the code running in the
 database
> itself, e.g PL/SQL / Java for Oracle. You might want to split that
 various
> field to different columns, but I'm not sure how much you would gain.
>
> --
>
> Thomas
>
>
> "Satish Kamatkar" <satish_at_marathimitra.com> wrote in message
> news:20df3b70.0106121938.11423974_at_posting.google.com...
> | Hi -
> |
> | I am about design a data model for a Calendar application. Here are
> | some basic requirements:
> |
> | 1...In this application events (Appointments - like in Outlook) can
 be
> | created. These events can be one time or they can be recurring. The
> | recurrance can be finite or infinite. i.e an event can occur every
> | Monday for current year OR an event can occur every day until end of
> | time.
> |
> | 2...Also user should be able to manage (modify/delete) each
 occurance
> | of a recurring event indivisually. The modification/updates to any
> | particular occurance of an event must not affect other occurances.
> |
> | My question would be what kind of tables/logic would be best to
 achive
> | this functionality?
> |
> | Any thoughts?
> |
> | Thanks,
> |
> | Satish
>
>
>
>
>
  Received on Sun Jul 22 2001 - 01:32:09 CEST