How do I change column default value in PostgreSQL?

How do I change column default value in PostgreSQL?

I've tr开发者_如何学运维ied:

ALTER TABLE ONLY users ALTER COLUMN lang DEFAULT 'en_GB';

But it gave me an error:

ERROR: syntax error at or near "DEFAULT"

'SET' is forgotten

ALTER TABLE ONLY users ALTER COLUMN lang SET DEFAULT 'en_GB';

If you want to remove the default value constraint, you can do:

ALTER TABLE <table> ALTER COLUMN <column> DROP DEFAULT;