[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.
>> > --
>> > AccessD mailing list
>> > AccessD at databaseadvisors.com
>> > http://databaseadvisors.com/mailman/listinfo/accessd
>> > Website: http://www.databaseadvisors.com
>> >
>> --
>> AccessD mailing list
>> AccessD at databaseadvisors.com
>> http://databaseadvisors.com/mailman/listinfo/accessd
>> Website: http://www.databaseadvisors.com
>>
>
>