On Wed, May 19, 2004 at 12:41:12PM -0400, Christopher Browne wrote: > This won't happen "implicitly." > > tutorial=# CREATE TABLE A (id serial primary key,foo text); > NOTICE: CREATE TABLE will create implicit sequence "a_id_seq" for "serial" column > "a.id" > NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "a_pkey" for table "a" > CREATE TABLE > tutorial=# drop table b; > DROP TABLE > tutorial=# CREATE TABLE B (id serial references A,bar text); > NOTICE: CREATE TABLE will create implicit sequence "b_id_seq" for "serial" column > "b.id" > CREATE TABLE > > I can suggest a couple of ways you might do this: > > 1. So long as the inserts take place within the scope of the same > transaction on the same connection, it would be safe to create > the B entry via currval for the sequence.
WRONG! As long as they're in the same session, it will work. The
transaction has nothing to do with it.
> tutorial=# begin;
> BEGIN
> tutorial=# insert into a (foo) values ('toto');
> INSERT 2587831 1
> tutorial=# insert into b (id, bar) values (currval('a_id_seq'), 'yellow brick road');
> INSERT 2587832 1
> tutorial=# commit;
> COMMIT
>
> Note that if you don't enclose it in BEGIN/COMMIT, the insert into b
> could pick up on changes from other concurrent sessions.
Nope. Even without the BEGIN/COMMIT and three hours between the two
statements, it will still work. All that matters is that they're in the
same session. Check the documentation.
--
Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.
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