How can I alter a field from bigint to character varying in postgresql?

Question

I get an error "incompatible types: bigint and character varying." but I know there usually is a trick to bypass this.

Answer 1

alter table abc alter column def type varchar using def::varchar;

Answer 2

Seems to work fine in PG 9.0, but if not in your version you can always convert to text first:

select 1::bigint::text::varchar;