Cisco.com offers account managers which three of these resources? ()
A. customer issue narratives
B. training and events
C. ordering information
D. products and services informatio
在Oracle中,下面哪条语句当COMM字段为空时显示0,不为空时显示COMM的值()。
A. select ename,nvl(comm.,0)from emp
B. select ename,null(comm.,0)from emp
C. SELECT ename,NULLIF(comm,0)FROM emp
D. SELECT ename,DECODE(comm.,NULL,0)FROM em