How to create script with Postgresql to parameterize the start value of a sequence

Question

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.

Answer 1

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