Re: ER Diagram Help

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sat, 29 Jul 2006 14:01:02 GMT
Message-ID: <ySJyg.28552$pu3.384855_at_ursa-nb00s0.nbnet.nb.ca>


J M Davitt wrote:

> maccessgirl_at_gmail.com wrote:
> 

>> Greetings,
>>
>> I posted a yesterday about help for a database I am working on. Well I
>> sat down and came up with some entities and attributes based on my
>> wishes and came up with the below. I'm going to list the criteria again
>>
>> Here is the situation. I need to create a animal shelter database on
>> the following criteria.
>>
>> Track those who adopt pets from shelter so that "thank you
>> " letters can be sent
>>
>> Track how many pets are adopted during any period of time,
>> such as by month or year
>>
>> Track how many animals are adopted by the same family. The
>> shelter only allows adoption if three months have passed from any
>> previous adoption
>>
>> Manage and remind for vaccinations, surgery and medical
>> treatments
>>
>> Store owners desired criteria and automatically be notified
>> when suitable animals arrive
>>
>> Here are the entities that I have come up with:
>> Pets
>> ID
>> Breed
>> Type
>> DOB
>> Gender
>> Color
>> Adoption Date
>>
>> Family
>> Name
>> ID
>> Customer Type (Individual, Store, Institution)
>> Street
>> City
>> State
>> Zip Code
>> Date of Adoption
>> 1 or more pets
>>
>> Desired Criteria
>> Animal
>> Age
>> Gender
>> Color
>> Current Vaccinations
>> Neutered/ Sprayed
>>
>> Medical Information
>> Vaccination ID
>> Surgery ID
>> Medical Treatment ID
>> Name
>> Date
>>
>> This is what I cam up with. Please critique and correct me to the hilt
>> on what I did wrong. Something tells me that I have a lot of
>> redundancy.
>>
>> Also, What would be the primary key... foreign key. Would someone
>> please explain to me the relationships the see in this situation
>>
>> Thanks in advance,
>> MACCESSGIRL
> 
> I would take Adoption Date out of Pets and Date of Adoption
> out of Families and make another entity - Adoptions - that
> related the two.
> 
> I don't think Pets alone is sufficient.  I suspect you need
> something for Pets taken in (that would have an Intake Date)
> and Pets adopted out.  In my world, those would be different
> tables.  Too, not all animals taken in will be adopted;
> where do they go?  More tables!
> 
> The Desired Criteria doesn't identify who has the want.  And
> you probably want to affix some sort of date and invent a rule
> that prevents them from lingering forever.
> 
> Treatments?  Your design suggests lots of other tables (all
> those IDs) that I don't think you need.  A categorizing code,
> description, date, perhaps the provider, and (of course)
> something identifying the animal are probably all you'll need.

Perhaps those tables and id's were required by something else in the homework assignment? Received on Sat Jul 29 2006 - 16:01:02 CEST

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