6. SQL 語法 UPDATE 之正確寫法為何？(A)UPDATE bookname FROM Books WHERE id = 2 SET bookname ='哈利波特'(B)UPDATE FROM Books WHERE id = 2 SET bookname = '哈利波特'(C)UPDATE Books WHERE id = 2 SET b ookname = '哈利波特'(D)UPDATE Books SET bookname = '哈利波特' WHERE id = 2。