SQL Server 查询对连续日期数据进行分组

Question

今天下午我有点“大脑衰退”，所以如果有人能帮忙处理这个 mssql 查询，那就太好了。

我有一个名为“seasons”的表，其中包含三列（还有更多但与示例无关）：seasonId、date、tariffId

SeasonId 是唯一键。 一个日期只能有一个关税编号，但一个关税编号可以有多个不同的日期。

例如：

seasonId  |  date      |  tariffId
----------------------------------
       1  | 1 jan 2009 |         1
       2  | 2 jan 2009 |         1
       3  | 3 jan 2009 |         2
       4  | 4 jan 2009 |         3
       5  | 5 jan 2009 |         3

我想让查询返回针对特定关税 ID 的日期序列/范围

例如使用上面的数据，它将返回以下内容：

FromDate  |  ToDate    |  TariffId
-----------------------------------
       1  | Jan 2009 2 | Jan 2009 1
       3  | Jan 2009 3 | Jan 2009 2
       4  | Jan 2009 5 | Jan 2009 3

这可能吗？

编辑 感谢您到目前为止的所有答案！我总是很惊讶你能得到这么多的回应！

但是，我的示例数据可能不够复杂，因为关税可以有 1 个或多个日期范围

seasonId  |  date      |  tariffId
----------------------------------
       1  | 1 jan 2009 |         1
       2  | 2 jan 2009 |         1
       3  | 3 jan 2009 |         2
       4  | 4 jan 2009 |         3
       5  | 5 jan 2009 |         3
       6  | 6 jan 2009 |         1
       7  | 7 jan 2009 |         1
       8  | 8 jan 2009 |         3

愿意：

FromDate   |     ToDate  |  TariffId
------------------------------------
1 Jan 2009 | 2 Jan 2009  |         1
3 Jan 2009 | 3 Jan 2009  |         2
4 Jan 2009 | 5 Jan 2009  |         3
6 Jan 2009 | 7 Jan 2009  |         1
8 Jan 2009 | 8 Jan 2009  |         3

想法？

感谢大家对此的帮助！这个网站太棒了！

Answer 1

首先是一些测试数据：

create table seasons (seasonId int primary key
    , "date" datetime not null unique
    , tariffId int not null)

insert into seasons values (1, '2009-01-01', 1)
insert into seasons values (2, '2009-01-02', 1)
insert into seasons values (3, '2009-01-03', 2)
insert into seasons values (4, '2009-01-04', 3)
insert into seasons values (5, '2009-01-05', 3)
insert into seasons values (6, '2009-01-06', 1)
insert into seasons values (7, '2009-01-07', 1)
insert into seasons values (8, '2009-01-08', 3)
-- add a tarrif with a datespan larger than 2
insert into seasons values (9, '2009-01-09', 4)
insert into seasons values (10, '2009-01-10', 4)
insert into seasons values (11, '2009-01-11', 4)

基于 Dave Barker 的回答，在内联视图中添加 row_number() 以便我们知道哪个是第一个最小值，哪个是第二个，等等。 （实际上由于一个日期不能有多个关税ID，所以我们不需要按关税ID进行分区。）

SELECT MinValues.Seasonid, MinValues.Date, MaxValues.Date, MaxValues.tariffid 
FROM (
    SELECT *, row_number() over (partition by tariffId order by "date") as RN 
      FROM [dbo].[Seasons] tbl1
     WHERE NOT EXISTS (SELECT * 
                         FROM [dbo].[Seasons] tbl2 
                        WHERE tbl1.seasonid - tbl2.seasonid = 1 
                          AND tbl1.tariffId = tbl2.tariffId)) as minValues
JOIN (
     SELECT *, row_number() over (partition by tariffId order by "date") as RN
       FROM [dbo].[Seasons] tbl1
      WHERE NOT EXISTS (SELECT *
                          FROM [dbo].[Seasons] tbl2 
                         WHERE tbl2.seasonid - tbl1.seasonid = 1 
                           AND tbl1.tariffId = tbl2.tariffId)) as maxValues
ON MinValues.TariffId = MaxValues.tariffId
and MinValues.RN = MaxValues.RN
order by MinValues.Date

结果：

1   2009-01-01 00:00:00.000 2009-01-02 00:00:00.000 1
3   2009-01-03 00:00:00.000 2009-01-03 00:00:00.000 2
4   2009-01-04 00:00:00.000 2009-01-05 00:00:00.000 3
6   2009-01-06 00:00:00.000 2009-01-07 00:00:00.000 1
8   2009-01-08 00:00:00.000 2009-01-08 00:00:00.000 3
9   2009-01-09 00:00:00.000 2009-01-11 00:00:00.000 4

Answer 2

SELECT min(date) as FromDate, MAX(date) as ToDate, tarifid
FROM seasons
GROUP BY tarifID

应该这样做。

Answer 3

SELECT min(date) as FromDate,MAX(date) as ToDate, tariffid FROM(
select s.*,ISNULL(
(SELECT MAX(seasonID) FROM seasons s1 WHERE s.tariffid <> s1.tariffid AND s1.seasonID < s.seasonID),0) as ranks from seasons s)r
GROUP BY tariffID,ranks

Answer 4

也许是这个？

select min(fromdate) as FromDate, max(todate) as ToDate, tarifid
from (

select min(date) as fromdate, null as todate, tarifid
from seasons
group by tarifid

union

select null, max(date), tarifid
from seasons
group by tarifid

) q
group by tarifid

Answer 5

您似乎找到了连续出现的关税 ID，然后在该连续出现中找到了日期的最小值和最大值。以下适用于您的示例数据，但我怀疑最终的连接需要一些调整，因为它感觉很臭。

SELECT MinValues.Seasonid, MinValues.Date, MaxValues.Date, MaxValues.tariffid 
FROM (
    SELECT * 
      FROM [dbo].[Seasons] tbl1
     WHERE NOT EXISTS (SELECT * 
                         FROM [dbo].[Seasons] tbl2 
                        WHERE tbl1.seasonid - tbl2.seasonid = 1 
                          AND tbl1.tariffId = tbl2.tariffId)) as minValues
JOIN (
     SELECT * 
       FROM [dbo].[Seasons] tbl1
      WHERE NOT EXISTS (SELECT *
                          FROM [dbo].[Seasons] tbl2 
                         WHERE tbl2.seasonid - tbl1.seasonid = 1 
                           AND tbl1.tariffId = tbl2.tariffId)) as maxValues
ON MinValues.TariffId = MaxValues.tariffId
AND (MinValues.SeasonId = MaxValues.Seasonid or MinValues.SeasonId +1 = MaxValues.Seasonid)