对“school”数据库进行一次完整备份,并保留该备份设备上已有的内容,备份到backup3备份设备上(假设此备份设备已创建好),使用( )语句。
A.
BACKUP DATABASE school TO backup3 WITH INIT
B.
BACKUP DATABASE school TO backup3 WITH DIFFERENTIAL ,NOINIT
C.
BACKUP DATABASE school TO backup3 WITH NOINIT
D.
BACKUP DATABASE school TO backup3 WITH DIFFERENTIAL ,INIT