I'm newbie in Postgres. I use Pgadmin III and I need to parameterize a value in a statament of 'alter sequence'. I have tried to execute this code:
select coalesce(MAX(ID)+1,1) as max into myTempTable from myTable;
EXECUTE immediate 'ALTER SEQUENCE mySequence INCREMENT BY 1 START WITH ' || max || ' MINVALUE 1 NO CYCLE';
but it doesn't work. What's wrong? I need to encapsulate it in a function? Thank you. D.
For setting value to sequence manually, you can use ALTER SEQUENCE seq_name RESTART WITH value
Regarding to your example, you need something like this:
CREATE SEQUENCE testseq;
DO $$
DECLARE
maxid INT;
BEGIN
SELECT coalesce(MAX(ID)+1,1) FROM myTable INTO maxid;
EXECUTE 'ALTER SEQUENCE testseq RESTART WITH '|| maxid;
END;
$$ LANGUAGE PLPGSQL
No need for dynamic SQL.
Just create the sequence and then change the current value:
create sequence mysequence increment by 1 minvalue 1 no cycle;
select setval('mysequence', (select coalesce(MAX(id)+1,1) from mytable));
You probably also want to make that sequence the default for that column:
alter table mytable alter column id
set default nextval('mysequence');
alter sequence mysequence owned by mytable.id;