CREATE TABLE STAFF (
  STAFF_ID number,
  STAFF_NAME varchar(30),
  DEPARTMENT_ID number,
  PRIMARY KEY(STAFF_ID),
  FOREIGN KEY(DEPARTMENT_ID) references DEPARTMENT(DEPARTMENT_ID))
);

CREATE TABLE department
(
   department_id             NUMBER,
   department_name           VARCHAR2 (30),
   department_block_number   NUMBER,
   CONSTRAINT department_pk PRIMARY KEY (department_id)
);


CREATE TABLE staff
(
   staff_id        NUMBER,
   staff_name      VARCHAR (30),
   department_id   NUMBER,
   CONSTRAINT staff_pk PRIMARY KEY (staff_id),
   CONSTRAINT department_fk FOREIGN KEY
      (department_id)
       REFERENCES department (department_id)
);