Fat Data Model vs Skinny Data Model

Rails
1

Ive recently been contemplating how to tackle allowing for extra
“fields” to be added to a recordset. For example, a user has an email
address, but they may also want to put their birthday, height, weight,
etc. I don’t want to constrain what is possible in this situation. I
think what I’m describing is best documented in Philip G.spun’s
page here:

http://philip.greenspun.com/seia/user-registration-and-management

Now, I’m not entirely sure this is the best approach, I’m open to
suggestions on how to deal with the situation. What I would like to
know though is: Is this something that could be an extension of the
ActiveRecord class? Lets say its called ActiveSkinnyRecord or
something… is there a potential to make tables with this setup be
just as easily dealt with as ActiveRecord does? Id be willing to give
it a shot if it makes sense to others, and is doable. Please let me
know your thoughts.

Joe N.

2

On 4/7/06, Joe N. [email protected] wrote:

Ive recently been contemplating how to tackle allowing for extra
“fields” to be added to a recordset. For example, a user has an email
address, but they may also want to put their birthday, height, weight,
etc. I don’t want to constrain what is possible in this situation.

You have at least three strategies available that you can use right
now without any futher additions to AR:

1.) Single Table Inheritance (admittedly not 100% what you’re looking
for, but it’s worth a mention anyway)
2.) has_many :attributes, :as => :attributable (polymorphic
relationship with a simple Attribute model)
3.) serialize :attributes (where User#attributes is a Hash that is
YAML’d into a TEXT column transparently.)

Go wild!

–

3

2.) has_many :attributes, :as => :attributable (polymorphic
relationship with a simple Attribute model)

Thanks Hendrik, I will check that out. I think the serialized way
while it may be convenient would probably be a bad deal for general
record finding/sorting… too bad cause that would be a real simple
solution.

Joe