CREATE TABLE MEDICINE (
   medicine_code CHAR (7) NOT NULL,
   med_name_sci VARCHAR (50) NOT NULL,
   med_name_common VARCHAR (50) NOT NULL,
   normal_dosage VARCHAR (300) NOT NULL,
   medicine_comments VARCHAR (500) NULL,
   quantity_stock INTEGER NULL CHECK (quantity_stock >= 0),
   unit_measure VARCHAR (20) NULL,
 PRIMARY KEY (medicine_code)
);