无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

單項(xiàng)選擇題

您要對(duì)EMPLOYEES表的FIRST_NAME和LAST_NAME列創(chuàng)建一個(gè)組合索引。以下哪條語句將完成此任務(wù)()

A.CREATE INDEXfl_idx ON employees(first_name last_name)
B.CREATE INDEXfl_idx ON employees(first_name),employees(last_name)
C.CREATE INDEXfl_idx ON employees(first_name,last_name)
D.CREATE INDEXfl_idx ON employees(first_name);CREATE INDEXfl_idx ON employees(last_name)

微信掃碼免費(fèi)搜題