You added a PHONE_NUMBER column of NUMBER data type to an existing EMPLOYEES table. The EMPLOYEES table already contains records of 100 employees. Now, you want to enter the phone numbers of each of the 100 employees into the table. Some of the employees may not have a phone number available. Which data manipulation operation do you perform? （）
1、During a period of whiteout，you should
During a period of whiteout，you should expect which of the following（）.ASnowfall or blowing snowBLack of ability to estimate distanceCHarsh contrast between sun-illuminated snow cover and the backgroundDHazy horizons with extensive mirage effect
You recently added a third-party application to your database and do not have access to th...
3、You perform a security audit of a ser
You perform a security audit of a server named DC1. You install the Microsoft Network Monitor 3.0 application on DC1.You plan to capture all ...
4、You are the administrator of a Window
You are the administrator of a Windows Server 2003 computer named Server1.Newly hired employees recently started storing files on Server1. Now u...
5、If you are given the job of adding hyd
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （...
6、You perform a security audit of a ser
You perform a security audit of a server named CRM1. You want to build a list of all DNS requests that are initiated by the server. You in...