multivalued attributes in databases

Question

How should a relational database be designed to handle multi-valued attributes ?

edit: To elaborate:

There are two ways I could think of for do

Answer 1

If you are limited to working with a strictly relational database, then you need to store those values as rows in a table. And that was your question - how to do it with a relational database. However, there are many databases available that provide native storage of multiple values in a field which turns out to be a very good match for much real world data, easy to program with, and simpler to comprehend (without the explosion of tables you get with 3rd normal form). For more info, see http://en.wikipedia.org/wiki/MultiValue http://en.wikipedia.org/wiki/IBM_U2 http://en.wikipedia.org/wiki/InterSystems