ﺑﻪ ﻣﻨﻈﻮر ﻣﺮﺗﺐﺳﺎزی ﻧﺰولی رﻛﻮردﻫﺎی ﺟﺪول ﺑﺮاﺳﺎس دو ﻓﻴﻠﺪ id,fname ﻛﺪام یک از دﺳﺘﻮرات زﻳﺮ ﺻﺤﻴﺢ اﺳﺖ؟
1 )
SELECT * FROM student ORDER BY id DESC , ORDER BY fname DESC
SELECT * FROM student ORDER BY id DESC , fname DESC
3 )
SELECT * FROM student ORDER BY id, fname DESC
4 )
SELECT * FROM student ORDER BY id AND fname DESC