Hi Roy,
On Jul 15, 2004, at 12:39 PM, McBrayer, Roy wrote:
> I have a question about primary keys in Cayenne. For tables, that do
> not
> have a primary key in the actual database, it appears that Cayenne
> requires
> me to designate a primary key.
Yes, as this is the basis of the ObjectId used to map an object to a DB
row.
> If a designate multiple fields as a primary key, does Cayenne use this
> as a combined key.
Yes.
> Also, can I create a primary key that is unrelated to the database and
> is just tracked internally by
> Cayenne?
No, as it breaks the ORM layer (see my first answer), so it must be a
combination of persistent fields. Just identify a combination of
columns that provide a unique identifier for the row in the DB. If it
is not possible with your database there are a few techniques that can
help, but it is hard to recommend anything without looking at your
schema and your requirements.
Andrus
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