From: Mat Schaffer <schapht@...>
Date: 2006-12-27T13:40:50+09:00
Subject: Re: Modified Single Table Inheritance

On Dec 26, 2006, at 5:51 PM, Ryan Glover wrote:
> My third solution, the one I am asking advice on, is this.
>
> I create a single table with the 4 common columns and a dozen columns
> with names such as float1, float2, float3, ... , string1, string2, ..
> etc.  Creating enough columns of each type to cover my largest  
> subclass.
> Then I use STI and for each class I map the generic columns to the  
> nicer
> names inside the subclasses.  So in one class float1 may be miles/hour
> while in another class it might be turkeys/hectare.
>
> Does this sound like a reasonable approach?
>
> Also, how would I map the generic names to nice names in my  
> subclasses?
> (I am a RoR noob)
>
> And of course, does anyone see a much better way to do what I have
> proposed?

Even though we're not technically on the RoR list, I thought this was  
still an interesting question for ORM, STI, OOP and probably some  
other acronyms too :)

I'd be curious to hear just what it is that you're doing that needs  
100s of classes, first.  Sounds like you might be taking OOP a bit  
too far for your purposes.

But to answer your question, I like the concept but it brings up fear  
of bugs.  Dropping meaningful column names will wreak havoc on any  
cases where you have to write a query by hand.  But everything is a  
trade off.  Personally, I'd try the 100s of tables route first and  
see how it panned out.

Best of luck.  Sounds like a tricky one.
-Mat