Rory,
> The issue is this:
> I need to make a database insert and then make an image with the
> resulting column id number, which is provided by a sequence.
I think you mean "primary key" or "row id", not "column id". There is
no "column id".
> This has to be a single action, otherwise I could fall into a race
> condition with another insert going on concurrently.
No, you can't. PostgreSQL sequences are guarenteed 100% unique
regardless of concurrent updates. Simply put:
BEGIN TRANSACTION;
INSERT INTO some_table ( columns )
VALUES ( values);
SELECT CURRVAL('some_table_seq');
COMMIT TRANSACTION;
Easy, no?
Now please go read the online docs, or better yet, buy an introductory
PostgreSQL book. There's a lot to learn.
-Josh Berkus
