How to set a Postgresql default value datestamp like 'YYYYMM'?

Question

As title, how can I set a table\'s column to have the default value the current year and month, in format \'YYYYMM\', like 200905 for today?

Answer 1

Just in case Milen A. Radev doesn't get around to posting his solution, this is it:

CREATE TABLE foo (
    key     int PRIMARY KEY,
    foo     text NOT NULL DEFAULT TO_CHAR(CURRENT_TIMESTAMP,'YYYYMM')
);