[mikr]

Hi all,
I am new here and also newbie to databases.

I am trying to create a database that will hold information about who owns a company. Something like this:

A company can be own by one or more persons or other companies. Ex.
Google is owned by:
Person1
Person2
Company1
Company2

Futhermore I would like to keep track of the history, how the ownership change over time.

How can this be done?

[r937]

2 googles 4 u 2 do: party datamodel and supertype/subtype

[dportas]

One possibility:

CREATE TABLE CompanyOwners_People
(CompanyId INT NOT NULL REFERENCES Companies (CompanyId),
Owner_PersonId INT NOT NULL REFERENCES People (PersonId));

CREATE TABLE CompanyOwners_Companies
(CompanyId INT NOT NULL REFERENCES Companies (CompanyId),
Owner_CompanyId INT NOT NULL REFERENCES Companies (CompanyId));

[dportas]

Oops. Just in case it wasn't obvious:

CREATE TABLE CompanyOwners_People
(CompanyId INT NOT NULL REFERENCES Companies (CompanyId),
Owner_PersonId INT NOT NULL REFERENCES People (PersonId),
PRIMARY KEY (CompanyId, Owner_PersonId));

CREATE TABLE CompanyOwners_Companies
(CompanyId INT NOT NULL REFERENCES Companies (CompanyId),
Owner_CompanyId INT NOT NULL REFERENCES Companies (CompanyId)
PRIMARY KEY (CompanyId, Owner_CompanyId));

[mikr]

This seems to work fine. Thank you. I did a quick try on OpenOffice - Base but it seems that the program does not like the double relation between "CompanyOwners_Companies" and "Companies". It allows me to define it but when I save it and reopen it's gone. Is this the normal behavior for this program or am I doing something wrong.