Visit website for the story and examples
N-Tuple is a collection of modules provides customized and extendable multi-component cck fileds capable representing/storing relations (of any-arity ) between drupal objects that developers can use in different ways:
1. Build multi-column fields
2. Per-column options
3. Assign each column a list of available values (bind each tuple cooordinate to an entity set domain/subdomain)
4. Advanced management of available values (managment of entities and domains)
5. Use it as base cck field for your module. (just implement your application specific logic)
6. Store arbirtary relations between almost any drupal entities (for example: you can create relation between: input format, user and node)
7. In your code you work with with just like any cck field
8. Api to store data in n-tuple fields
9. Node local task to import data from csv into n-tuple cck fields