如何在Oracle中找到两个大小范围之间缺少的大小范围？

Posted 2021-04-17

我想验证两个尺寸范围之间缺少的尺寸范围。例如，现在我有一个名为AQL的表，该表包含以下列：

    ID  TYPE        SIZE_FROM  SIZE_TO
    --  ----------  ---------  -------
    68  NORMAL      2          150
    69  NORMAL      501        1200
    70  REDUCED     1201       3200
    71  REDUCED     151        500

我需要找出缺少的范围是：

    TYPE       SIZE_FROM  SIZE_TO
    ---------  ---------  -------
    NORMAL     151        500
    REDUCED    501        1200

我已经处理了重叠部分，那么该怎么做才能选择以下缺失范围？

答案

有关示例数据，请参阅是否有帮助（阅读代码中的注释）：

SQL> with
  2  aql (id, type, size_from, size_to) as
  3    -- Your current data
  4    (select 68, 'NORMAL' ,   2,  150  from dual union all
  5     select 69, 'NORMAL' ,  501, 1200 from dual union all
  6     select 70, 'REDUCED', 1201, 3200 from dual union all
  7     select 71, 'REDUCED',  151,  500 from dual
  8    ),
  9  existing_sizes as
 10    -- list all existing sizes, one-by-one, per type
 11    (select  type, size_from + column_value - 1 csize
 12     from aql cross join table(cast(multiset(select level from dual
 13                                             connect by level <= size_to - size_from + 1
 14                                            ) as sys.odcinumberlist))
 15    ),
 16  minmax as
 17    -- find MIN and MAX size valze per type - will be used in ALLSIZES CTE
 18    (select type, min(size_from) size_from, max(size_to) size_to
 19     from aql
 20     group by type
 21    ),
 22  allsizes as
 23    -- list all sizes (per type) between MIN and MAX value
 24    (select type, size_from + column_value - 1 csize
 25     from minmax cross join table(cast(multiset(select level from dual
 26                                                connect by level <= size_to - size_from + 1
 27                                               ) as sys.odcinumberlist))
 28    ),
 29  missing_sizes as
 30    -- missing sizes can be found with MINUS set operator
 31    (select a.type, a.csize from allsizes a
 32     minus
 33     select e.type, e.csize from existing_sizes e
 34    )
 35  -- the final result
 36  select type, min(csize) size_from, max(csize) size_to
 37  from missing_sizes
 38  group by type;

TYPE     SIZE_FROM    SIZE_TO
------- ---------- ----------
NORMAL         151        500
REDUCED        501       1200

SQL>

但是，如果涉及更多的差距，这将失败（但这不是您的示例数据所建议的）。