如何按顺序生成重复数字

Question

我想生成此序列

col sequence 
  01 01
  01 02
  01 03 
  01 04
  01 05
  02 01
  02 02
  02 03
  02 04
  02 05
  ..
  ..
  12 01
  12 02
  12 03
  12 04
  12 04

并将其作为序列添加到另一个选择中。

Answer 1

分层查询可能有助于产生您发布的结果：

SQL> with
  2  c1 as
  3    (select lpad(1 + level - 1, 2, '0') col1
  4     from dual
  5     connect by level <= 12
  6    ),
  7  c2 as
  8    (select lpad(1 + level - 1, 2, '0') col2
  9     from dual
 10     connect by level <= 5
 11    )
 12  select c1.col1, c2.col2
 13  from c1 cross join c2
 14  order by c1.col1, c2.col2;

CO CO
-- --
01 01
01 02
01 03
01 04
01 05
02 01
02 02
02 03
02 04
02 05
03 01
03 02
<snip>
11 04
11 05
12 01
12 02
12 03
12 04
12 05

60 rows selected.

SQL>

Answer 2

您想要row_numner()：

select col, row_number() over (partition by col order by col) as sequence
from table t;

您可以使用子查询进行进一步的操作。