create table emp(    no			number(12) not null,    upd_ts		date not null,    name		char(20) not null,    duty		char(1) not null,    age			number(6) not null,    salary		number(12,2) not null,    primary key (no));insert into emp values(0,sysdate,'??0','1',20,1000);insert into emp values(2,sysdate,'??2','1',20,1000);commit;