첫번째 답 - A
create table mysales (prod_id, cust_id, quantity_sold, price)
as
select product_id, customer_id, quantity_sold, price
from sales
where 1 = 2; -- where 절로 인한 0행 출력
두번째 답 - C
-- 테스트 1
alter table emp
add constraint emp_pk primary key(ename);
alter table emp
add constraint emp_uk unique(comm);
create table emp2(ename, sal, comm)
as
select ename, sal, comm
from emp;
--테스트 2
create table emp3 (
ename varchar2(20) not null,
sal number(10) not null,
comm number(10) not null
);
create table emp4
as
select ename, sal, comm
from emp3;
desc emp;
다음검색