A.FOR INSERT B.FOR UPDATE C.FOR DELETE D.FOR REFRESH
A.信息 B.数据 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.视图 B.索引 C.存储过程 D.触发器
A.SET SERVEROUTPUT ON B.DECLARE C.BEGIN END D.EXCEPTION
