Design - New to database design, seeking consult

Hi

I am an architectural graduate student with nil experience designing and developing databases. I understand how they work on a schematic level though I am not up on the terminology. I have played only superficially with Access and Visio and I understand that Blog type websites have databases (controlled by PHP?) managing any posts...

What I am looking to do s create a database that I can then feed some visualization program - think cytoscape, semaspace, tulip, prefuse etc etc - that would illustrate relationships between different entries in a network form...show how they are related, and hopefully be able to have some sort of "pivot" (MS terminology) function where the self-organsing nodes of the network would readjust as per the field being queried.

Here's the real scenario, which also brings me to the real reason I am here : I am looking at the design of a zoo, and I am building a database of animals which will describe a number of attributes about each species. The question I have is how a REAL database designer would handle a scenario where there are potentially multiple entries for a field...like if I wanted a field for the continents you would find a particular species on - what would you do if there are multiple continents? If I were to have a drop down menu with a number of choices i would only be able to choose one. The only way I have imagined it potentially working is to have a number of continent fields, say 3, and some animals might fill those in while others might not.

Is that how YOU would do it? Can you suggest a better way, or a better place to ask this question?

Also, if you can think of a better workflow to get from the bits of info I am culling from the web, to inputting it into Excel and then bringing it into one of the aforementioned packages...I would appreciate hearing your thoughts.

Thanks!

1) database design is nothing like dropdown listings (though you can also select multiple values in those if you know how).
2) What exactly are you trying to do? write an application for a problem you have and you are at the database design step?
3) when designing a database - I like to use 3rd Normal Form - so if multiple fields can have multiple values (m-n) - I use bridge (associative) tables.

so for your example you would have an animal table, a continent table and an animal_continent table (where the primary keys of each are given to make the connection)

let me know if you need more information - don not have the time right now to go indepth. there are a couple of places to learn about design - start on http://www.geekgirls.com/databases_from_scratch_1.htm

first off, thanks for the link. as for your list of three items...I am at the design of the database step. I have an excel spreadsheet of data I have put together but I think it needs to be assembled into multiple tables as you have suggested.

As for your suggestions of three tables, one for animals, one for continents, and one tying the two together, what will this third one look like? In the animal table I have each species listed out and I presume I can use their name as their ID (or is it primary key). The same can probably be said for the continent table. For the one which ties the two together I am confused about what each "record" will look like....Can you describe it more for me? Is eash entry a continent and then all the animals that can be found on that continent to its right?

Thanks so much for your help.
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I was trying to make a simple ERD of what I am talking about but it was too difficult. anyway - in the bridge table you are just holding the primary key of the animal table and the primary key of the continent table. this makes your many to many relationships into one ot many.

thanks.

I got it figured out. Now the problem is...how to visualize these relationships. I was going to use GraphML which consists of nodes (entities) and edges (relationships between nodes)...the only problem that I see is that it doesnt seem like you can create relationships on the fly...relationships are made explicit and are single state conditions. If I wanted to see all the animals that belonged to a single continent but than change the web of relations so that I was viewing all the ungulates above a certain size...well I dont think this will do it. I think I need some new technology. Any ideas how to create such a visualisation (or query, that can produce more than just names, and maybe even with a swift and intuitive interface)???

thanks....