How to make flexible models and associations

Question

Hi,

I am trying to design a very flexible model like google docs survey.

It's a bulletin board post model. And admin(or site builder) can add boards freely. But instead of fixed columns, admin can define additional columns. So the post model can be used for many other purposes.

I have currently 2 models - board and post. A board has many posts.

A post has columns like subject, content, writer_id. It could have additional columns as an admin wishes. The additional column could be an integer, a string, a date, or a text.

How would you model such a case?

Thanks.

Sam

Answer 1

http://en.wikipedia.org/wiki/Entity-attribute-value%5Fmodel