你有很多基于验证方式的变体：

with data(order_num, qty) as (
    select '34905', 2 from dual union all
    select '39754', 5 from dual
)
select order_num || '-' || level as newsequence
from data
connect by level <= qty and prior order_num = order_num 
    and prior sys_guid() is not null
;

with data(order_num, qty) as (
    select '34905', 2 from dual union all
    select '39754', 5 from dual
)
select order_num ||'-'|| column_value as new_sequence
from data,
lateral
(
    select level as column_value from dual
    connect by level <= qty
);

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...

你将需要一个域来生成序列。这里我使用了一个带有常量的cte，你可以使用1和max qty之间的递归cte（或者你有这样的数字表）：

with num(n) as ( values (1),(2),(3),(4),(5)) 
select o.orderno || '-' || cast(num.n as varchar(2))
from num
join orders o
    on o.qty >= num.n
order by o.orderno, n;

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Fiddle
使用数字表，如

insert into numbers (n)
select 1 from dual
union all
select 2 from dual
union all
select 3 from dual
union all
select 4 from dual
union all
select 5 from dual;

型
您可以将查询编写为：

select o.orderno || '-' || cast(numbers.n as varchar(2))
from numbers
join orders o
    on o.qty >= numbers.n
order by o.orderno, n;

型

这是某种类型的行生成器，正如你已经被告知的那样。在 * 较低 * Oracle数据库版本（我的意思是低于23c）中工作的版本是：
样本数据：

SQL> with test (c_order, qty) as
  2    (select 34905, 2 from dual union all
  3     select 39754, 5 from dual
  4    )

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查询：

5  select c_order ||'-'|| column_value as new_sequence
  6  from test cross join
  7    table(cast(multiset(select level from dual
  8                        connect by level <= qty
  9                       ) as sys.odcinumberlist));

NEW_SEQUENCE
--------------------------------------------------------------------------------
34905-1
34905-2
39754-1
39754-2
39754-3
39754-4
39754-5

7 rows selected.

SQL>

型