1

Please can someone clarify something which I should really know by now?

If I have Three Entitys Organisation, Director and Company secretary and each have the attribute primary address.

If I were modelling a conceptual ERD should I have the attribute ‘primary address’ separately in each entity or should I model a fourth entity Address, add primary address and have them all PK > FK to that?

Have since found this link Is this a good way to model address information in a relational database? which pretty much covers everything I need to know.

Community
  • 1
  • 1
Pixelated
  • 1,531
  • 3
  • 15
  • 35
  • Will the Primary Address be the same across all related entities? Or it is possible that the organization's primary address will differ from Director / Company Secretary. The way i've done this in the past was to have a Organization have locations, with one of those locations being primary. – Doon Aug 04 '10 at 14:15
  • Hi Doon, Many thanks for the response, yes all three primary addresses may differ as director and organisation may not be related. Cheers for the advice though as I may be able to apply that to another problem I'm having. – Pixelated Aug 04 '10 at 14:59

1 Answers1

0

I would do something like this, assuming primary address refers to the Organization location:

Table: Organization

Org_Key {PK},
Org_Name,
Primary Address fields,
Any other fields

Table: Personnel

Person_Key {PK},
Org_Key {FK},
Position {Directory, secretary, etc},
Any other fields

In my opinion, there is really no need to separate those who are "Directors" from those who are "secretaries" because they are both employees of a specific Organization.

Now, if by primary address you mean a personal address (i.e., an individuals home address) then I would add additional fields to the Personnel table.

ajdams
  • 2,276
  • 14
  • 20
  • Hi Ajdams, many thanks for the response in my situations the directors and comp secretaries might not be related with any of the organisations in which I'm modelling. So primary address for organisation could be there registered address and primary address for Director could be their residential address. In which case I guess I could add an address table with multiple address types which link to each Entity (org, director and secretary)? – Pixelated Aug 04 '10 at 14:26