S12_2:6

INSERT INTO copy_f_staffs(id,first_name,last_name,birthdate,salary,overtime_rate,training,staff_type,manager_id,manager_budget,manager_target)
VALUES(25,'Kai','Kim',TO_DATE('03-Nov-1988','fmdd-Mon-yyyy'),6.75,NULL,NULL,'Order Taker',NULL,NULL,NULL);

S12_3:3 B:

CREATE TABLE manager_copy_d_cds
AS ( SELECT * FROM d_cds);


C:

INSERT INTO manager_copy_d_cds(cd_number,title,producer,YEAR)
VALUES(20,'Hello World Here I Am','Middle Earth Records','1998')

D:

MERGE INTO manager_copy_d_cds tgt USING d_cds src
ON (src.cd_number = tgt.cd_number)
WHEN MATCHED THEN UPDATE
SET  tgt.title = src.title, tgt.producer = src.producer, tgt.YEAR = src.YEAR
WHEN NOT MATCHED THEN INSERT
VALUES (src.cd_number, src.title, src.producer, src.YEAR);