Question

我需要创建一份清单，列出英国的2所评级酒店，它们从一开始就至少提高了3分。

Month       | Hotel | Rating | Region |
---------------------------------------
01-Jan-19   | A     | 1      |  US    |
01-Feb-19   | B     | 2      |  UK    |
01-Mar-19   | C     | 3      |  EU    |
01-Apr-19   | A     | 1      |  US    |
01-May-19   | B     | 4      |  UK    |
01-Jun-19   | C     | 3      |  EU    |
01-Jul-19   | A     | 1      |  US    |
01-Aug-19   | B     | 5      |  UK    |
01-Sep-19   | C     | 4      |  EU    |

像这样，查询必须仅生成酒店 B 。

Answer 1

听起来您想要第一个和最后一个条目。一种方法使用条件聚合。我将假设month实际上是日期或数字，而不是字符串：

select t.hotel
from (select t.*,
             row_number() over (partition by hotel order by month asc) as seqnum_asc,
             row_number() over (partition by hotel order by month desc) as seqnum_desc
     from t
    ) t
group by t.hotel
having max(rating) filter (where seqnum_asc = 1) >= max(rating) filter (where seqnum_desc = 1) + 3;

Answer 2

这也有效

我尝试过

Select "Hotel"

From T

Where "Region" = 'UK'

Group by "Hotel"
                Having 
                        Min ("Rating") = 2
                And 
                        Max ("Rating") >= 5

测试链接：

https://www.db-fiddle.com/f/6TVgrC5WRjqdyPwdGSvWGN/8

一定时间内的汇总

2 个答案: