On May 12, 2:22 pm, d-42 <db.****s...@[EMAIL PROTECTED]
> wrote:
> On May 12, 9:57 am, d.kinn...@[EMAIL PROTECTED]
wrote:
>
> > I am in the process of moving a database from Access to Filemaker. One
> > field is giving me some problems working out the best way to handle
> > it. The date fields have the format of yyyymmdd with "99999999"
> > representing "forever" or "does not expire".
>
> > I can im****t the dates into the new data base with a calculation to
> > change to the fm date format BUT how can I handle the "forever" dates?
> > OR would it be best to define all of these as numbers with some kind
> > of calculation for input validation?
>
> 'Forever' is not a valid date, and 'magic numbers' that mean something
> special are generally bad design. The 'correct' way to handle it is
> with 2 fields. An number field acting like a boolean (true/false) for
> 'does not expire'.
>
> Alternatively you can define a text field, and have it store 'forever'
> or a date as text, but it doesn't really get you anywhere useful,
> because you will have to apply conversions to work with the date; e.g.
> to perform finds, etc.
>
> If you want 'forever' or a date to appear in a single 'place' on
> layouts, you just define an unstored text calc... if(doesnotexpire =
> 1,"forever", expirydatefield)
>
> -cheers,
> Dave
The steps I would take are
1. Im****t the date information from access to a TEXT field
2. Use a calculation to transfer all of the valid dates to a date
field (for non-expiring, either leave the date field blank or put
12/31/2099. NOTE: if you intend to do finds based on the expiration
date, and you want non-expiring records to be included, make sure you
do the latter)
3. Set a boolean like Dave suggested for the non-expiring
Cheers,
Kevin
|
