Thread: Serial Data Type
I have just created a table using SELECT INTO however the PK was supposed to be a serial. It is now an integer. To make it a serial I just create the seq and set the default to be the nextval() of that sequence right? is there anything else I need to do? It'll maintain the transactional safety of a serial created default, right? I.e., it'll not rollback seq values on a transaction abortion will it? Thanks, - Naz.
> I have just created a table using SELECT INTO however the PK was > supposed to be a serial. It is now an integer. To make it a serial I > just create the seq and set the default to be the nextval() of that > sequence right? is there anything else I need to do? You'll want to do this: ALTER SEQUENCE table_col_id_seq OWNED BY table.col_id; http://www.postgresql.org/docs/8.3/interactive/sql-altersequence.html > It'll maintain the > transactional safety of a serial created default, right? I.e., it'll > not rollback seq values on a transaction abortion will it? Yes
On Wed, Apr 2, 2008 at 10:12 PM, Naz Gassiep <naz@mira.net> wrote: > I have just created a table using SELECT INTO however the PK was > supposed to be a serial. It is now an integer. To make it a serial I > just create the seq and set the default to be the nextval() of that > sequence right? is there anything else I need to do? It'll maintain the > transactional safety of a serial created default, right? I.e., it'll not > rollback seq values on a transaction abortion will it? > Thanks, not quite. you also have to set the sequence to a higher number than the highest currently inserted key of the table. you do this with setval...watch out for the is_called property. also you should lock the table first...otherwise you would get a race if someone inserts a value into the table between the time when you calculate the value for setval and you assign it to the sequence. so (pseudo code here): begin; lock table foo; setval('the_sequence, (select max(foo_id) from foo), true); alter table foo alter foo_id default nextval('the_sequence'); alter sequence the_sequence owned by foo.foo_id; -- h/t to adam rich commit;
"Adam Rich" <adam.r@sbcglobal.net> writes: >> I have just created a table using SELECT INTO however the PK was >> supposed to be a serial. It is now an integer. To make it a serial I >> just create the seq and set the default to be the nextval() of that >> sequence right? is there anything else I need to do? > You'll want to do this: > ALTER SEQUENCE table_col_id_seq OWNED BY table.col_id; > http://www.postgresql.org/docs/8.3/interactive/sql-altersequence.html That's correct as far as it goes, but the OP might benefit more from reading the description of what a "serial" column really is: http://www.postgresql.org/docs/8.3/interactive/datatype-numeric.html#DATATYPE-SERIAL regards, tom lane