OK, I figured out how to drop the primary key and change the NULLS. So it looks like this now:
CREATE TABLE public.gz_life_mammals
(
id integer NOT NULL,
taxon text NOT NULL,
parent text NOT NULL,
slug text,
namecommon text,
plural text,
extinct smallint NOT NULL,
rank smallint NOT NULL,
key smallint NOT NULL,
CONSTRAINT "Unique Key" UNIQUE (taxon)
)
WITH (
OIDS=FALSE
);
ALTER TABLE public.gz_life_mammals
OWNER TO postgres;
