Storing arrays in db

Hi,

My users can select items and define a quantity attribute for those. Those items can be selected with checkboxes. And the quantity is a field text.

Collecting all in one form; the checkbox selections, and other details, the info should be stored in the db. Resulting in a purchase order for example. A single user wouldn't have many purchase orders in the system at one time.

My question is how to store the resulting array in the db? I know how to get the array of values but what should I use as the container in the db, a single row with a sting hash, store each item separately, something else? How can I relate the quantity for each item?

The available items are not predefined, and users can create new items into the system also.

I think it is pretty trivial stuff but I would like to get the models and logic right from the beginning. Any good suggestions/tutorials?

Thanks.

Just off the top of my head, i'd think you'd want your purchase order class to has_many :items through :some_join_model. The quantity would be stored on the join model.

Fred