Topic: Quick ER model help.

Hey there!
I'm new to the RoR community and been tinkering with RoR for a while now. I've decided to write a simple app that allows users to "build a phone" by selecting certain "parts" from a form on my app. The user selects a combination of parts(limited to 5) and the app totals it up and proceeds to payment while notifying admins.

I know it sounds simple but I'm having a few problems with modelling the entire thing. Each "part" has a "part_type" attribute and each field in the form allows you to select a certain part_type. I'm also having problems actually populating dropdown menus straight from a database.

I'd like to know the best(and fastest of course) way to go about doing this. I'm well versed with HTML/CSS/JS/SQL if that's a plus.
Again, thanks a lot!

Re: Quick ER model help.

So what exactly is your problem:  Where are you stuck modeliing the application domain model?

Speaking about part_type:  are you already using Single Table Inheritance there?