sql - 如何在 SQL 中将顺序的、带时间戳的行组合在一起并返回每个组的日期范围

Question

我有一个 MS SQL 2008 数据库表，如下所示：

Registration | Date | DriverID | TrailerID

一些数据的示例如下：

AB53EDH,2013/07/03 10:00,54,23
AB53EDH,2013/07/03 10:01,54,23
...
AB53EDH,2013/07/03 10:45,54,23
AB53EDH,2013/07/03 10:46,54,NULL <-- Trailer changed
AB53EDH,2013/07/03 10:47,54,NULL
...
AB53EDH,2013/07/03 11:05,54,NULL
AB53EDH,2013/07/03 11:06,54,102  <-- Trailer changed
AB53EDH,2013/07/03 11:07,54,102
...
AB53EDH,2013/07/03 12:32,54,102
AB53EDH,2013/07/03 12:33,72,102  <-- Driver changed
AB53EDH,2013/07/03 12:34,72,102

如您所见，数据表示在任何时间点哪个驾驶员和哪个拖车附加到哪个注册。我想做的是生成一个报告，其中包含驱动程序和拖车的每个组合都处于活动状态的时段。因此，对于上面的示例数据，我想生成如下所示的内容：

Registration,StartDate,EndDate,DriverID,TrailerID
AB53EDH,2013/07/03 10:00,2013/07/03 10:45,54,23
AB53EDH,2013/07/03 10:46,2013/07/03 11:05,54,NULL
AB53EDH,2013/07/03 11:06,2013/07/03 12:32,54,102
AB53EDH,2013/07/03 12:33,2013/07/03 12:34,72,102

您将如何通过 SQL 执行此操作？

更新：感谢到目前为止的答案。不幸的是，当我将其应用于我拥有的生产数据时，它们停止了工作。到目前为止提交的查询在应用于部分数据时无法正常工作。

下面是一些示例查询，用于生成数据表并使用上面的虚拟数据填充它。此处的数据比上例中的数据多：驱动程序、拖车组合 54,23 和 54,NULL 已重复，以确保查询识别出这是两个不同的组。我还使用不同的日期范围将相同的数据复制了三次，以测试在部分数据集上运行查询是否有效：

CREATE TABLE [dbo].[TempTable](
    [Registration] [nvarchar](50) NOT NULL,
    [Date] [datetime] NOT NULL,
    [DriverID] [int] NULL,
    [TrailerID] [int] NULL
)

INSERT INTO dbo.TempTable
VALUES 
('AB53EDH','2013/07/03 10:00', 54,23),
('AB53EDH','2013/07/03 10:01', 54,23),
('AB53EDH','2013/07/03 10:45', 54,23),
('AB53EDH','2013/07/03 10:46', 54,NULL),
('AB53EDH','2013/07/03 10:47', 54,NULL),
('AB53EDH','2013/07/03 11:05', 54,NULL),
('AB53EDH','2013/07/03 11:06', 54,102),
('AB53EDH','2013/07/03 11:07', 54,102),
('AB53EDH','2013/07/03 12:32', 54,102),
('AB53EDH','2013/07/03 12:33', 72,102),
('AB53EDH','2013/07/03 12:34', 72,102),
('AB53EDH','2013/07/03 13:00', 54,102),
('AB53EDH','2013/07/03 13:01', 54,102),
('AB53EDH','2013/07/03 13:02', 54,102),
('AB53EDH','2013/07/03 13:03', 54,102),
('AB53EDH','2013/07/03 13:04', 54,23),
('AB53EDH','2013/07/03 13:05', 54,23),
('AB53EDH','2013/07/03 13:06', 54,23),
('AB53EDH','2013/07/03 13:07', 54,NULL),
('AB53EDH','2013/07/03 13:08', 54,NULL),
('AB53EDH','2013/07/03 13:09', 54,NULL),
('AB53EDH','2013/07/03 13:10', 54,NULL),
('AB53EDH','2013/07/03 13:11', NULL,NULL)

INSERT INTO dbo.TempTable
SELECT Registration, DATEADD(M, -1, Date), DriverID, TrailerID
FROM dbo.TempTable
WHERE Date > '2013/07/01'

INSERT INTO dbo.TempTable
SELECT Registration, DATEADD(M, 1, Date), DriverID, TrailerID
FROM dbo.TempTable
WHERE Date > '2013/07/01'

Answer 1

此查询使用 CTE 来：

1. 创建按注册分组的有序记录集合
2. 对于每条记录，捕获前一条记录的数据
3. 比较当前和以前的数据以确定当前记录是否是驱动程序/拖车分配的新实例
4. 仅获取新记录
5. 对于每条新记录，获取新的驱动程序/拖车分配发生之前的最后日期

链接到SQL 小提琴

下面的代码：

;WITH c AS (
-- Group records by Registration, assign row numbers in order of date
SELECT
  ROW_NUMBER() OVER (
    PARTITION BY Registration 
    ORDER BY Registration, [Date]) 
  AS Rn,
  Registration,
  [Date],
  DriverID,
  TrailerID
FROM 
  TempTable
)
,c2 AS (
-- Self join to table to get Driver and Trailer from previous record
SELECT 
  t1.Rn,
  t1.Registration,
  t1.[Date],
  t1.DriverID,
  t1.TrailerID,
  t2.DriverID AS PrevDriverID,
  t2.TrailerID AS PrevTrailerID
FROM 
  c t1
LEFT OUTER JOIN 
  c t2
ON 
  t1.Registration = t2.Registration
AND 
  t2.Rn = t1.Rn - 1 
)
,c3 AS (
-- Use INTERSECT to determine if this record is new in sequence
SELECT
  Rn,
  Registration,
  [Date],
  DriverID,
  TrailerID,
  CASE WHEN NOT EXISTS (
            SELECT DriverID, TrailerID 
            INTERSECT 
            SELECT PrevDriverID, PrevTrailerID) 
       THEN 1
       ELSE 0
  END AS IsNew
FROM c2 
) 
-- For all new records in sequence, 
-- get the last date logged before a new record appeared
SELECT 
  Registration,
  [Date] AS StartDate,
  COALESCE (
    (
       SELECT TOP 1 [Date]
       FROM c3 
       WHERE Registration = t.Registration
       AND Rn < (
         SELECT TOP 1 Rn
         FROM c3 
         WHERE Registration = t.Registration 
         AND Rn > t.Rn 
         AND IsNew = 1 
         ORDER BY Rn )
       ORDER BY Rn DESC 
    )
    , [Date]) AS EndDate,
  DriverID,
  TrailerID
FROM 
  c3 t
WHERE
  IsNew = 1 
ORDER BY 
  Registration,
  StartDate

Answer 2

这是一种使用相关子查询的方法：

with tt as (
       select tt.*,
              (select top 1 date
               from TempTable tt2
               where tt2.Registration = tt.Registration and
                     tt2.DriverID = tt.DriverID and
                     (tt2.TrailerID = tt.TrailerID or tt2.TrailerID is null and tt.TrailerID is null) and
                     tt2.Date < tt.Date
               order by date desc
              ) prevDate
       from TempTable tt
      )
select registration, min(date) as startdate, max(date) as enddate, driverid, trailerid
from (select tt.*,
             (select top 1 date
              from tt tt3
              where prevDate is NULL and
                    tt3.Date <= tt.date
              order by Date desc
             ) as grp
      from TempTable tt
     ) tt
group by grp, Registration, DriverID, trailerid;

CTE 正在lag(date)对注册、driverid 和 trailid 进行检查，生成上一个日期以供记录。这是NULL一系列记录的开头。

然后，子查询在给定记录上或之前的 NULL 记录上查找最近的日期。这充当分组变量。grp在这一点上，序列中的所有内容都相同。

最终查询将其聚合为您想要的格式。

这是一个复杂的查询。在 SQL Server 2012 中，可以使用lag()和 累积聚合函数稍微简化语法。使用这些功能，您可以遵循基本相同的方法。

编辑：

哎哟。上述查询在计算上一个日期时存在逻辑错误。该修复需要假设日期在数据中是唯一的。

上面的错误是它查找三列匹配的上一个日期。哑巴，哑巴，哑巴。因为在数据中可能存在匹配但更早的三元组。相反，它需要获取上一个日期，然后查看三重匹配。

下面通过一个额外的连接来实现这一点。它在SQL Fiddle 上运行。

with tt as (
       select tt.*, tt3.date as PrevDate
       from (select tt.*,
                    (select top 1 date
                     from TempTable tt2
                     where tt2.date < tt.date
                     order by date desc
                   ) prevDate1
             from TempTable tt
            ) tt left outer join
            TempTable tt3
            on tt.prevdate1 = tt3.date and
               tt3.Registration = tt.Registration and
               tt3.DriverID = tt.DriverID and
               (tt3.TrailerID = tt.TrailerID or tt3.TrailerID is null and tt.TrailerID is null)
     )
select registration, count(*), min(date) as startdate, max(date) as enddate, driverid, trailerid
from (select tt.*,
             (select top 1 date
              from tt tt3
              where prevDate is NULL and
                    tt3.Date <= tt.date
              order by Date desc
             ) as grp
      from TempTable tt
     ) tt
group by grp, Registration, DriverID, trailerid;

Answer 3

尝试-：

DECLARE @TempTable AS TABLE (
    [Registration] [nvarchar](50) NOT NULL,
    [Date] [datetime] NOT NULL,
    [DriverID] [int] NULL,
    [TrailerID] [int] NULL
)

INSERT INTO @TempTable
VALUES 
('AB53EDH','2013-07-03 10:00', 54,23),
('AB53EDH','2013-07-03 10:01', 54,23),
('AB53EDH','2013-07-03 10:45', 54,23),
('AB53EDH','2013-07-03 10:46', 54,nULL),
('AB53EDH','2013-07-03 10:47', 54,NULL),
('AB53EDH','2013-07-03 11:05', 54,NULL),
('AB53EDH','2013-07-03 11:06', 54,102),
('AB53EDH','2013-07-03 11:07', 54,102),
('AB53EDH','2013-07-03 12:32', 54,102),
('AB53EDH','2013-07-03 12:33', 72,102),
('AB53EDH','2013-07-03 12:34', 72,102)

SELECT t1.Registration, MIN(t1.Date) AS StartDate, MAX(t1.date) AS EndDate, t1.DriverID, t1.TrailerID
FROM @TempTable AS t1
INNER JOIN @TempTable AS t2
    ON t1.Registration = t2.Registration AND (t1.DriverID = t2.DriverID OR t1.TrailerID = t2.TrailerID)
GROUP BY t1.Registration, t1.DriverID, t1.TrailerID
    ORDER BY MIN(t1.Date)