Обсуждение: Getting the next sequence value safely

Hi,

I have a situation where I want to insert a record into a table
which will give the record a unique id via a sequence.  Is there
an easy and safe way to get this id number either right before
or right after the insertion?  My best idea is to select last_value
from the sequence and then assume that the record will get
last_value + 1 when it is inserted (the insertion would happen
right after the select).  Is this a safe assumption?
What happens if I wrap these operations in a transaction?  Is
there a standard way of doing this?

Thanks,
--Jeremy

Jeremy,

No just do a select nextval('sequencename') and then insert it with the
result.

Dave
On Fri, 2002-06-07 at 17:24, Jeremy Buchmann wrote:
> Hi,
>
> I have a situation where I want to insert a record into a table
> which will give the record a unique id via a sequence.  Is there
> an easy and safe way to get this id number either right before
> or right after the insertion?  My best idea is to select last_value
> from the sequence and then assume that the record will get
> last_value + 1 when it is inserted (the insertion would happen
> right after the select).  Is this a safe assumption?
> What happens if I wrap these operations in a transaction?  Is
> there a standard way of doing this?
>
> Thanks,
> --Jeremy
>
>
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