[AccessD] Normalization discussion

Susan Harkins ssharkins at gmail.com
Fri Aug 29 13:52:17 CDT 2014


Seriously? I would love to do it this way -- nobody but me will ever work
on it.

Susan H.


On Fri, Aug 29, 2014 at 2:42 PM, Rocky Smolin <rockysmolin at bchacc.com>
wrote:

> Since this is a small database used by a few people, you can make life easy
> for yourself.  Put all the  fields you need for each of the three type of
> acquisition into the Animal table.  I would also not bother with an
> Acquisition Type table with a PK and an FK in the animal table. Just (gasp)
> put the words Live Birth, Acquisition, or Law Enforcement right in the
> Acquisition Type field (text).  Unnormalized?  Yes.  Simple?  Yes.  And
> easy
> to see when you look in the back end.
>
> In the front end if you want to get fancy, you can appear and/or disappear
> the different fields you need depending on acquisition type.  Or
> enable/disable. But not necessary.
>
> R
>
>
> -----Original Message-----
> From: accessd-bounces at databaseadvisors.com
> [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Susan Harkins
> Sent: Friday, August 29, 2014 10:54 AM
> To: Access Developers discussion and problem solving
> Subject: Re: [AccessD] Normalization discussion
>
> What I'm struggling with today is acquisitions. There are three ways that
> we
> acquire an animal -- live birth here at the center, from an institution, or
> through law enforcement confiscation (almost never happens, but I'm
> allowing
> for the possibility). So, each animal has an acquisition type, but
> depending
> on the type the subsequent data will be different. For example, if a live
> birth here at the center, we will also track the dam and sire ids. If we
> acquire an animal from an institution, we'll track the institution's info,
> like name, address, phone, and a contact.
>
> So, an animal has an acquisition id by type. It's easy to keep an
> institution and live birth table -- that's no problem. But how do I relate
> them back to the individual since it can come from two different tables? I
> think this is probably easier than I'm making it.
>
> Susan H.
>
>
> On Fri, Aug 29, 2014 at 11:39 AM, Susan Harkins <ssharkins at gmail.com>
> wrote:
>
> > Right now, most of my foreign keys in the parent table are simple
> lookups.
> > For instance, species -- each individual has a species and those are
> > in a child table. We'll update that table infrequently -- only if we
> > add a new species. We have several individuals of each species.
> > Another is gender -- female and male, but the parent table has a
> > foreign key to the gender table. (Gender's probably overkill, but I'm
> > on autopilot I think). I'm also tracking acquisition method -- there
> > are only three, so again, it's a lookup table and not a true child table.
> >
> > Susan H.
> >
> >
> >
> >
> >
> >
> >
> >
> > On Fri, Aug 29, 2014 at 10:18 AM, Charlotte Foust <
> > charlotte.foust at gmail.com> wrote:
> >
> >> A foreign key is a key that points to the PK in another table.
> >> You're mixing keys with parent child relationships, which are defined
> >> through keys.  In a data warehouse, you put a bunch of keys in the
> >> central table, but in a regular database you put the parent PK into
> >> the child tables so they know their mommy,  The idea is to put the keys
> where they are needed.
> >>
> >> Charlotte
> >>
> >>
> >> On Fri, Aug 29, 2014 at 6:07 AM, Susan Harkins <ssharkins at gmail.com>
> >> wrote:
> >>
> >> > I'll spend the morning rereading the book Martin and I wrote,
> >> > brushing
> >> up
> >> > on the normalization part. I've forgotten a lot of the basics. I'm
> >> writing
> >> > an animal tracing database in Access and I'm trying to remember if
> >> > it matters where the fk goes. Now, I remember its purpose and all
> >> > that,
> >> but it
> >> > would be so much simpler if I could just drop them all into the
> >> > main
> >> table
> >> > instead of adding a fk to all the child tables to the main table --
> >> > I
> >> think
> >> > anyway.
> >> >
> >> > So, I've got a main table of animals and all of the remaining
> >> > tables are child tables of a sort and a few lookup tables. Is it
> >> > reasonable to just add a fk to all those child tables in my parent
> table?
> >> >
> >> > I just don't remember. I haven't built a database in...
> >> > seriously... 10 years? It's been long enough that I'm really
> struggling.
> >> >
> >> > Susan H.
> >> > --
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