（单选题）
Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns: LAST NAME VARCNAR2(35) NOT NULL SALARY NUMBER(9,2) NOT NULL COMMISION_PCT NUMBER(4,2) Which statement ensures that a value is displayed in the calculated columns for all employees? （）
ASELECT last_name, 12*salary* commission_pct FROM emp;
BSELECT last_name, 12*salary* (commission_pct,0) FROM emp;
CSELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;
DSELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;
正确答案
答案解析
略
