[AccessD] Checkboxes/MultiSelect Listbox - What's Best?

Drew:

In the old IBM 360 days, there was something called alignment where if you
defined a byte field it had to be aligned on a word boundary anyway so you
didn't save any space. (IIRC.  Which is doubtful, in any event. )

Do you think it's the same in Jet where the byte field really takes up more
than a byte?

Rocky

----- Original Message ----- 
From: <DWUTKA at marlow.com>
To: <accessd at databaseadvisors.com>
Sent: Monday, February 16, 2004 6:04 PM
Subject: RE: [AccessD] Checkboxes/MultiSelect Listbox - What's Best?


> Not sure why a handful of boolean fields is not normalized.....
>
> However, Jet does two bytes for a boolean field.  Which is a waste of 15
> bits! However, Unless you have a ton of records and/or have a massive
amount
> of boolean fields, the space wasted is negligible.
>
> However, if you really want a method to cram them into one field, I would
> recommend a simple Byte field, versus a string field.  First of all, with
a
> string field, you will be using more space.....sort of.  At a minimum, a
> string field takes up one byte. (Which tells Jet how long the data in the
> field is.).  Then you would have 2 bytes (A97, and ASCII) per item, in
your
> example (AS, DI, etc.).  However, with a Byte Field, you have 8 bits to
turn
> 'off' and 'on', so you can represent up to 8 'programs' with one byte
field.
>
> Still don't see a real advantage here.....unless you are dealing a heavily
> coded interface, then dealing with the bits is going to be faster then
> pulling strings apart.
>
> Drew
>
> -----Original Message-----
> From: accessd-bounces at databaseadvisors.com
> [mailto:accessd-bounces at databaseadvisors.com]On Behalf Of Terri Jarus
> Sent: Monday, February 16, 2004 3:56 PM
> To: access Developers discussion and problem solving
> Subject: [AccessD] Checkboxes/MultiSelect Listbox - What's Best?
>
>
> I'm redesigning an existing database that is not fully normalized.  Here
is
> an example where I'm not sure the best way to handle.  Current db has a
> field (Boolean) for each program:  AS, DI, MS, SS, LB, NU for example and
> the user checks the applicable box(es) that are related to their contract.
>
> I was going to use a Multiselect Listbox and have it save a string value
to
> the field Programs - but, I would  need the string value to be in a
> consistent order.
>
> Another idea would be to save a record for each program in a Programs
table.
>
> Which is the best route to follow?  Any suggestions?
>
> If you need more information, just let me know.  Thank you for your input.
>
> Terri Jarus
> Director, Contract Support Services
> jarus at amerinet-gpo.com
> 314-542-1902
>
>
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