【oracle sql】给某表增加一个timestamp字段并设定时间

【SQL】

create table emp_0322(
    id number(12),
    name nvarchar2(20),
    primary key(id)
)

insert into emp_0322
select rownum,
       dbms_random.string('*',dbms_random.value(20,20))
from dual
connect by level<11;

alter table emp_0322 add(cdate timestamp(9));

update emp_0322 set cdate=to_date('2022.3.22','yyyy.MM.dd')+id where 1=1 

END