CREATE TABLE enzyme (id NUMBER, name CLOB, location CLOB, product CLOB, chromosome CLOB, omim NUMBER, porphyria CLOB)
CREATE TABLE medicine_enzyme_interaction (enzyme_id NUMBER, medicine_id NUMBER, interaction_type CLOB)
CREATE TABLE medicine (id NUMBER, name CLOB, trade_name CLOB, fda_approved CLOB)

How many different FDA approval statuses exist for medicines?
SELECT COUNT(DISTINCT fda_approved) FROM medicine
SELECT COUNT(DISTINCT "fda_approved") FROM "medicine"