Oracle認(rèn)證綜合練習(xí)單項(xiàng)選擇題每日一練(2020.05.20)

A.FOR INSERT
B.FOR UPDATE
C.FOR DELETE
D.FOR REFRESH

A.信息
B.數(shù)據(jù)
C.文本
D.文件

A.select * from emp where comm='';
B.select * from emp where comm=null;
C.select * from emp where nvl(comm)=0;
D.select * from emp where comm is null;
E.select * from emp where nvl(comm,0)=0;

A.視圖
B.索引
C.存儲(chǔ)過程
D.觸發(fā)器

A.SET SERVEROUTPUT ON
B.DECLARE
C.BEGIN END
D.EXCEPTION