create table t01(num number);
insert into t01 values(1);
insert into t01 values(3);
insert into t01 values(5);
insert into t01 values(7);
insert into t01 values(9);
insert into t01 values(2);
insert into t01 values(4);
insert into t01 values(6);
insert into t01 values(8);
insert into t01 values(10);
commit;
create table t02(num number);
-- 测试一，不使用PL/SQL，直接查询
select num
from
(
select num
from t01
order by num desc
) tmp01
where rownum<=5;
-- 测试二，使用PL/SQL匿名块，将查询结果插入t02表，子查询使用order by
begin
insert into t02(num)
select num
from
(
select num
from t01
order by num desc
) tmp01
where rownum<=5;
end;
/
-- 测试三，使用PL/SQL匿名块，将查询结果插入t02表，子查询“不”使用order by
begin
insert into t02(num)
select num
from
(
select num
from t01
) tmp01
where rownum<=5;
end;
/
