sql - 在 Oracle 中使用 sql 查找日期范围中的差距

Question

我需要使用 sql 查找基本日期范围和测试范围之间的差距。这是我的示例 SD 和 ED 是开始日期和结束日期。 A 和 B 的所有行都在同一个表中。

A 的日期

ID    SD            ED
 A   20130101      20130531
 A   20130601      20131031

B 的日期

 ID  SD            ED
 B   20130120      20130420
 B   20130601      20130830
 B   20130910      20131130

Output should be: 
the Dates that are in A but are not in B with no dates overlaps

缺少间隙范围

SD           ED
20130101     20130119
20130421     20130531
20130831     20130909

我在这里看了一些例子 http://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:529176000346581356 但他们没有像我这样的场景。

Answer 1

select 
   to_char(SD, 'yyyymmdd') as SD,
   to_char(ED, 'yyyymmdd') as ED
from
   (  -- prepare gaps in each A after removing all B
      select
         BED + 1 as SD,
         lead(BSD, 1, AED + 1) over (partition by ASD,AED order by BSD) - 1 as ED
      from
         (  -- prepare all intersections between A and B
            select AA.sd as ASD, AA.ed as AED, BB.sd as BSD, BB.ed as BED
            from AA join BB on least(AA.ed, BB.ed) >= greatest(AA.sd, BB.sd)
            union all
            select AA.sd, AA.ed, to_date('1000','yyyy'), AA.sd - 1
            from AA
         )
   )   
where SD <= ED  -- exclude empty gaps
order by 1

fiddle