Mike Clements wrote:
> Up to now, we were selecting the current value of the sequence
> immediately after the insert. I thought this was safe because
> transactions should be isolated. But now I realize this could
> potentially fail because the default transaction isolation is "read
> committed". Thus if another connection inserts into the same table,
> causing the sequence to increment, if it commits before we read the
> sequence value, we might read the wrong value (the value as incremented
> by the other transaction, not the value as it was for our own insert).
You should use the lastval-function. It retrieves the last value
returned in your connection. "SELECT lastval('sequence')"
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com