Re: Identity key?
From: DODO <dodo_at_Ihatespam.com>
Date: Mon, 8 Jan 2001 14:45:37 -0500
Message-ID: <BNo66.115497$Z2.1364234_at_nnrp1.uunet.ca>
Date: Mon, 8 Jan 2001 14:45:37 -0500
Message-ID: <BNo66.115497$Z2.1364234_at_nnrp1.uunet.ca>
> A surrogate key is created by the database system for its own use and
> it is never exposed to the user. Artifical keys are created by the
> users and they are exposed. These two terms get confused. I don't
Then in the example
CREATE TABLE US_States
(state_id IDENTITY,
state_code CHAR(2) NOT NULL PRIMARY KEY,
state_name VARCHAR(15) NOT NULL UNIQUE);
state_id would be an artificial key? And you think that is useless? What happens if the state_code is changed by the standard comitee?
> What you want is a natural key, if one exists and is easy to record.
What is a natural key?
TIA,
DODO
Received on Mon Jan 08 2001 - 20:45:37 CET