如何查询非连续值？

Question

我在名为 的表中有一列id:1, 3, 4, 9, 10, 11t_mark

如何获得非连续范围？（例如[1, 3]，[4, 9]）

Answer 1

或者，使用LEAD分析函数以及您喜欢的格式。TESTCTE 是您已经拥有的；第 9 行开始就是您所需要的。

SQL> with test (col) as
  2    (select 1  from dual union all
  3     select 3  from dual union all
  4     select 4  from dual union all
  5     select 9  from dual union all
  6     select 10 from dual union all
  7     select 11 from dual
  8    ),
  9  temp as
 10    (select col,
 11            lead(col) over (order by col) lcol
 12     from test
 13    )
 14  select '[' || col ||' - '|| lcol ||']' result
 15  From temp
 16  where lcol - col > 1
 17  order by col;

RESULT
-------------------------------------------------------
[1 - 3]
[4 - 9]

SQL>

[编辑：调整，这样你就不必考虑太多]

这就是你所拥有的：

SQL> select * From t_mark;

      M_ID
----------
         1
         3
         4
         9
        10
        11

6 rows selected.

这就是您所需要的：

SQL> with temp as
  2    (select m_id,
  3            lead(m_id) over (order by m_id) lm_id
  4     from t_mark
  5    )
  6  select '[' || m_id ||' - '|| lm_id ||']' result
  7  From temp
  8  where lm_id - m_id > 1
  9  order by m_id;

RESULT
------------------------------------------------------------------
[1 - 3]
[4 - 9]

SQL>

基本上，您应该学习如何使用 CTE（公共表表达式，又名with Factoring 子句）。