1. There's some debate as to what to use for an identity field, I use the identity
included with the db (or the sequence in Oracle) and i also make that the primary key.
It's the easiest way. It does have a limitation when it reaches a high number, but
that number is potentially huge and your db would probably need a clean up by that
time anyways. Imagine how many rows you could get in a 15 digit number?
2. Not sure, but generally you don't need to worry about it as stated above, but
based on programming knowledge, it would probably roll over and start again.
3. Can't have a primary key on non-unique values (can you?)
Travis
---- Original Message ----
From: "CT, Loo" <[EMAIL PROTECTED]>
Sent: 2002-01-03
To: SQL <[EMAIL PROTECTED]>
Subject: Questions
Dear SQL gurus,
I have some questions on database design and hope all experts out there
can give me some ideas/advice.
Please advise/comment on the followings:-
1. Should one use the identity field as primary key in designing a
database?
If yes, isn't it has a limitation when the number reaches its
limits?
2. What would happens to the database when the identity field's value
reaches its limits?
3. Any advice on selecting a primary key for a table where none of the
columns has unique value?
Thanks in advance.
Kind regards,
CTLoo
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