Question

I am having a brain-cease on a data problem that I am in need of modeling. I will do my best to outline the tables, and relationships

users (basic user information name/etc)
users.id

hospitals (basic information about hospital name/etc)
hospitals.id

pages
pages.id
user_id (page can be affiliated with a user)
hospital_id (page can be affiliated with a hospital)

Here is where the new data begins, and I am having an issue

groups (name of a group of pages)
groups.id

groups_pages (linking table)
group_id
page_id

Now here is the tricky part .. a group can be ‘owned’ by either a user or hospital, but those pages arent necessarily affiliated with that user/hospital .. In addition, there is another type of entity (company) that can ‘own’ the group

When displaying the group, I will need to know of what type (user / hospital / company) the group is and be able to get the correct affiliated data (name, address, etc)

Im drawing a blank on how to link groups to its respective owner, knowing that its respective owner can be different.

Answer 1

• Party is a generic term for person or organization.
• Keep all common fields (phone no, address..) in the Party table.
• Person and Hospital should have only specific fields for the sub-type.
• If the company has different set of columns from Hospital simply add it as another subtype.
• If Hospital and company have same columns, rename the Hospital to more generic Organization
• PartyType is the discriminator {P,H}