Re: ALTER TABLE ( smallinto -> boolean ) ... - Mailing list pgsql-hackers

"Marc G. Fournier" <scrappy@postgresql.org> writes:
> # ALTER TABLE table ALTER COLUMN field1 type boolean;
> ERROR:  column "field1" cannot be cast to type "pg_catalog.bool"

> Should this not work?

No, because there's no built-in cast from smallint to bool.  You could
do something like

... type boolean using case when field1=0 then false else true end;
        regards, tom lane