Re: Synthesize support for Statement.getGeneratedKeys()?

Dave Cramer wrote:
>>
>> 3) Is there a) an efficient RETURNING clause to pre-populate the
>> generated-keys result set, or b) should I synthesize it.
>
> I take it from this that you are intending on returning all generated
> columns?, just generated columns that have keys ?
>>

Yes, ideally. I'd prefer not to try and synthesize the values from only
a single (last or first row's) key, since sequences can have increment
values other than one, and because OIDs are not predictable (are they?).
Other server generated key types also seem to make the synthetic idea
unfeasible.

>> 4) If 3b is required, then besides incrementing (by one) sequences,
>> any suggestions on how to correctly synthesize other increment values?
>> Other key types (OIDs, etc?)
>
> Are you suggesting here that you are planning on incrementing the
> sequences by 1 ? Why not just let the insert occur and get the currval
> of the sequence ?

I'm thinking what you're thinking; get the current value; however the
increment I mention is just in case I cant get more than one curval... I
don't know, can I get 3 values from RETURN if I insert three VALUEs in
one query??

>>
>> 5) To be absolutely sure, inserting multiple values then getting the
>> sequence back (RETURNING) will happen atomically in the server, correct?
>> (to avoid getting another transaction's keys).
> You don't want to return the sequence, as it can be changed by another
> transaction, you want to return the value in the row that was inserted.
>>

Agreed.