Company & Contacts Object Design Help

Answer 1

If you are trying to desing a database, I'd do it that way :

Companies = [id, name]
Contacts = [id, name]
Products = [id, name]
Adresses = [id, details]

CompaniesContacts = [contact_id, company_id]
CompaniesProducts = [product_id, company_id]
AdressesContacts = [contact_id, address_id]

References = [contact_id, referenced] // referenced is also a contact_id

Also, I'd recommend using UML. It's just a quick answer, try to update your question and I'll update it a bit.

Answer 2

We have a similar structure in our application and it works well for us. We have two extra tables

We have the concept of Sites between the company and addresses people can be attached one or more sites in our schema and that saves storing thousands of duplicate addresses. You could reference the client address direct in an addressbook too.

Where are you storing contact details ?

Answer 3

You can use the following object model:

Organization
-id
-name
-description
-productLines ( collection object consisting of products)
-orgcontacts ( collection object consisting of contacts)
-addresses (of type Address, can be a collection depends on business rule)

Contact
-id
-name
-type (Business, personal, etc)
-parentID (null if no reference)
-adresses (Address or collection)

ProductLine
-id
-name
-prLineContacts ( collection object consisting of contacts)

You can build on this basic model that I can think of. Do you have a data schema? if so, you should decide where to start. Some people like 1-1 mapping between their object and data model and some want to design their data schema based on performance and then have another abstraction mapping between objects and database.