Postgresql row_number 不按日期排序

Question

我正在研究 postgres 9.3.2，我有这个表:

id  startdate   enddate    no_of_days_between

1   2010-12-22  2010-12-23  1
1   2010-12-23  2010-12-24  1
1   2010-12-24  2010-12-25  1
1   2010-12-25  2010-12-26  1
1   2010-12-26  2010-12-27  1
1   2010-12-27  2010-12-28  1
1   2010-12-28  2010-12-29  1
1   2010-12-29  2011-03-06  67
1   2011-03-06  2011-03-07  1
1   2011-03-07  2011-03-08  1
1   2011-03-08  2011-03-09  1

我想要做的是找到连续几天的记录。为此，我在此查询中使用 row_number 窗口函数:

select t.*, row_number() over (partition by no_of_days_between order by enddate) as no_of_consecutive_days from t

我想要返回的是这样的:

id  startdate   enddate    no_of_days    no_of_consecutive_days 
                            _between
1   2010-12-22  2010-12-23  1            1
1   2010-12-23  2010-12-24  1            2
1   2010-12-24  2010-12-25  1            3
1   2010-12-25  2010-12-26  1            4
1   2010-12-26  2010-12-27  1            5
1   2010-12-27  2010-12-28  1            6
1   2010-12-28  2010-12-29  1            7 
1   2010-12-29  2011-03-06  67           1
1   2011-03-06  2011-03-07  1            1
1   2011-03-07  2011-03-08  1            2
1   2011-03-08  2011-03-09  1            3

但是查询返回的内容更像是先按 no_of_days_ Between 排序，然后按 enddate 排序，所以我返回:

id  startdate   enddate    no_of_days    no_of_consecutive_days 
                            _between
1   2010-12-22  2010-12-23  1            1
1   2010-12-23  2010-12-24  1            2
1   2010-12-24  2010-12-25  1            3
1   2010-12-25  2010-12-26  1            4
1   2010-12-26  2010-12-27  1            5
1   2010-12-27  2010-12-28  1            6
1   2010-12-28  2010-12-29  1            7 
1   2011-03-06  2011-03-07  1            8
1   2011-03-07  2011-03-08  1            9
1   2011-03-08  2011-03-09  1            10
1   2010-12-29  2011-03-06  67           1

有人遇到过这个问题吗？如何强制它先排序再分区？

谢谢

Answer 1

您仍然需要在查询末尾添加“ORDER BY enddate”，否则行的顺序就是 postgres 想要给您的任何顺序。

OVER 子句中的 ORDER BY 仅控制 row_number() 如何查看数据，而不控制数据最终如何返回。