UserSCOTTexecutesthefollowingcommandontheEMPtablebuthasnotissuedCOMMIT,ROLLBACK,oranydatadefinitionlanguage(DDL)command:SQL>SELECTenameFROMempWHEREjob=’CLERK’FORUPDATEOFempno;SCOTThasopenedanothersessiontoworkwiththedatabaseinstance.WhichthreeoperationswouldwaitwhenissuedinSCOTT’ssecondsession()
A.LOCKTABLEempINSHAREMODE;
B.LOCKTABLEempINEXCLUSIVEMODE;
C.UPDATEempSETsal=sal*1.2WHEREjob=ANAGER?UPDATEempSETsal=sal*1.2WHEREjob=?ANAGER?
D.INSERTINTOemp(empno,ename)VALUES(1289,’Harry’);
E.SELECTenameFROMempWHEREjob=’CLERK’FORUPDATEOFempno
第1题:
You‘ve configured an interface with an IP address and commited the change. You then commited a change that added an exception in a firewall filter to allow this network through the filter. You realize that this work was done on the wrong router.How do you undo all these changes?()
A. rollback 2
B. rollback 1
C. rollback 0
D. rollback 3
第2题:
第3题:
26、关于 ROLLBACK 的描述, 正确的是_______
A.ROLLBACK 语句会将事务对数据库的更新写入数据库
B.ROLLBACK 语句会将事务对数据库的更新撤消
C.ROLLBACK 语句会退出事务所在程序
D.ROLLBACK 语句能够将事务中使用的所有变量置空值
第4题:
A.DROP
B.ALTER
C.DELETE
D.ROLLBACK
第5题:
ROLLBACK语句用于回滚事务。