SQL查找从多个重叠间隔中经过的时间

Question

未使用MSSQL或DB2或Oracle。没有CTE。没有重叠谓词。没有INTERVAL数据类型。情况:对一辆待修的车辆进行修理工作要等到为这项工作订购的所有零件都已收到。在开始维修之前，零件可以订购多次。我们需要提取车辆处于"零件等待"状态的时间

对于标识为id = 1的车辆在4个不同的场合下订购零件(d1)和收到零件(d2)

    ID     d1     d2
     1     8/1    8/8
     1     8/2    8/6
     1     8/12   8/14
     1     8/3    8/10
 8/1                             8/8
  d1                              d2   
  |-------------------------------|  
         8/2             8/6                    8/12      8/14                  
         d1               d2                     d1        d2     
          |---------------|                      |----------|    
                   8/3                 8/10
                   d1                    d2
                   |---------------------|   
 8/1                                                       8/14
  |---------------------------------------------------------|  = 13 days
                                        8/10    8/12
  |--------------------------------------|    +  |----------|  = parts hold  = 11 days

从上面可以看出，开始工作的等待时间(假设8/1为车辆可用于工作的日期为13天。实际等待零件的时间是11天，这是数字我们需要从数据中推导。实际的datetime数据将是时间戳，我们将从中提取小时，为了表示简单，我们在这个示例数据中使用了日期。我们正在努力生成一个基于集合(不是psm，不是udf，不是游标)的解决方案。TIA

Answer 1

我无法得到@Alex W的查询工作。它不是标准的SQL，所以它需要大量的重写才能与SQL Server兼容(我可以测试)。但它确实给了我一些灵感，我已经扩展了。

---

求每段不间断等待的所有起始点:

SELECT DISTINCT
    t1.ID,
    t1.d1 AS date,
    -DATEDIFF(DAY, (SELECT MIN(d1) FROM Orders), t1.d1) AS n
FROM Orders t1
LEFT JOIN Orders t2                   -- Join for any events occurring while this
    ON t2.ID = t1.ID                  -- is starting. If this is a start point,
    AND t2.d1 <> t1.d1                -- it won't match anything, which is what
    AND t1.d1 BETWEEN t2.d1 AND t2.d2 -- we want.
GROUP BY t1.ID, t1.d1, t1.d2
HAVING COUNT(t2.ID) = 0

和端点的等效:

SELECT DISTINCT
    t1.ID,
    t1.d2 AS date,
    DATEDIFF(DAY, (SELECT MIN(d1) FROM Orders), t1.d2) AS n
FROM Orders t1
LEFT JOIN Orders t2
    ON t2.ID = t1.ID
    AND t2.d2 <> t1.d2
    AND t1.d2 BETWEEN t2.d1 AND t2.d2
GROUP BY t1.ID, t1.d1, t1.d2
HAVING COUNT(t2.ID) = 0

n为距离某公共时间点的天数。起点为负值，终点为正值。这样我们就可以把它们加起来，得到两者之间的天数。

span = end - start
span = end + (-start)
span1 + span2 = end1 + (-start1) + end2 + (-start2)

最后，我们只需要把东西加起来:

SELECT ID, SUM(n) AS hold_days
FROM (
   SELECT DISTINCT
       t1.id,
       t1.d1 AS date,
       -DATEDIFF(DAY, (SELECT MIN(d1) FROM Orders), t1.d1)  AS n
   FROM Orders t1
   LEFT JOIN Orders t2
      ON t2.ID = t1.ID
      AND t2.d1 <> t1.d1
      AND t1.d1 BETWEEN t2.d1 AND t2.d2
   GROUP BY t1.ID, t1.d1, t1.d2
   HAVING COUNT(t2.ID) = 0
   UNION ALL
   SELECT DISTINCT
       t1.id,
       t1.d2 AS date,
       DATEDIFF(DAY, (SELECT MIN(d1) FROM Orders), t1.d2) AS n
   FROM Orders t1
   LEFT JOIN Orders t2
      ON t2.ID = t1.ID
      AND t2.d2 <> t1.d2
      AND t1.d2 BETWEEN t2.d1 AND t2.d2
   GROUP BY t1.ID, t1.d1, t1.d2
   HAVING COUNT(t2.ID) = 0
   ORDER BY ID, date
) s
GROUP BY ID;

输入表(Orders):

ID   d1           d2
 1   2011-08-01   2011-08-08
 1   2011-08-02   2011-08-06
 1   2011-08-03   2011-08-10
 1   2011-08-12   2011-08-14
 2   2011-08-01   2011-08-03
 2   2011-08-02   2011-08-06
 2   2011-08-05   2011-08-09

输出:

ID   hold_days
 1          11
 2           8

---

或者，您可以使用存储过程来完成此操作。

CREATE PROCEDURE CalculateHoldTimes
    @ID int = 0
AS
BEGIN
    DECLARE Events CURSOR FOR
    SELECT *
    FROM (
        SELECT d1 AS date, 1 AS diff
        FROM Orders
        WHERE ID = @ID
        UNION ALL
        SELECT d2 AS date, -1 AS diff
        FROM Orders
        WHERE ID = @ID
    ) s
    ORDER BY date;
    DECLARE @Events_date date,
            @Events_diff int,
            @Period_start date,
            @Period_accum int,
            @Total_start date,
            @Total_count int;
    OPEN Events;
    FETCH NEXT FROM Events
    INTO @Events_date, @Events_diff;
    SET @Period_start = @Events_date;
    SET @Period_accum = 0;
    SET @Total_start = @Events_date;
    SET @Total_count = 0;
    WHILE @@FETCH_STATUS = 0
    BEGIN
        SET @Period_accum = @Period_accum + @Events_diff;
        IF @Period_accum = 1 AND @Events_diff = 1
            -- Start of period
            SET @Period_start = @Events_date;
        ELSE IF @Period_accum = 0 AND @Events_diff = -1
            -- End of period
            SET @Total_count = @Total_count +
                DATEDIFF(day, @Period_start, @Events_date);
        FETCH NEXT FROM Events
        INTO @Events_date, @Events_diff;
    END;
    SELECT
        @Total_start AS d1,
        @Events_date AS d2,
        @Total_count AS hold_time;
END;

调用:

EXEC CalculateHoldTimes 1;

Answer 2

这条SQL语句似乎得到了您想要的(t是样例表的表名):

SELECT
   d.id, 
   d.duration, 
   d.duration - 
   IFNULL(
      ( SELECT Sum( timestampdiff( SQL_TSI_DAY, 
                                   no_hold.d2, 
                                   ( SELECT min(d1) FROM t t4 
                                     WHERE t4.id = no_hold.id and t4.d1 > no_hold.d2 )))
        FROM ( SELECT DISTINCT id, d2 FROM t t1 
               WHERE ( SELECT sum( IIF( t1.d2 between t2.d1 and t2.d2, 1, 0 ) ) 
                       FROM t t2 WHERE t2.id = t1.id and t2.d2 <> t1.d2 ) = 0 
             And d2 <> ( select max( d2 ) from t t3 where t3.id = t1.id )) no_hold
        WHERE no_hold.id = d.id ),
      0 ) "parts hold"
FROM 
   ( SELECT id, timestampdiff( SQL_TSI_DAY, min( d1 ), max( d2 ) ) duration
     FROM t GROUP BY id ) d

外部查询获取修复工作的持续时间。复杂子查询计算不等待部件的总天数。这是通过定位车辆没有等待零件的开始日期，然后计算距离再次开始等待零件的天数来完成的:

// 1) The query for finding the starting dates when the vehicle is not waiting for parts, 
// i.e. finding all d2 that is not within any date range where the vehicle is waiting for part.
// The DISTINCT is needed to removed duplicate starting "no hold" period.
SELECT DISTINCT id, d2 
FROM t t1
WHERE ( SELECT sum( IIF( t1.d2 between t2.d1 and t2.d2, 1, 0 ) ) from t t2 
        WHERE t2.id = t1.id and t2.d2 <> t1.d2 ) = 0 AND 
      d2 <> ( SELECT max( d2 ) FROM t t3 WHERE t3.id = t1.id ) )

//2)车辆不等待零件的天数是从上述查询到车辆再次等待零件的日期

timestampdiff( SQL_TSI_DAY, no_hold.d2, ( SELECT min(d1) FROM t t4 WHERE t4.id = no_hold.id and t4.d1 > no_hold.d2 ) )

结合以上两点，并将所有这些时间加起来，得出车辆不等待零件的天数。最后一个查询添加了一个额外的条件来计算来自外部查询的每个id的结果。

对于具有许多id的大型表，这可能不是非常有效。如果id被限制为一个或几个，应该没问题。

Answer 3

USE [DnnMasterShoraSystem]
GO
/****** Object:  StoredProcedure [dbo].[CalculateHoldTimes]    Script Date: 12/8/2014 1:36:12 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[CalculateHoldTimes]
    @PID int    
AS
BEGIN      
CREATE TABLE #tblTemp(
    [ID] [int] NOT NULL,
    [PID] [int] NOT NULL,
    [BID] [int] NOT NULL,
    [Active] [bit] NULL,
    [WorkStartDate] [nvarchar](10) NULL,
    [WorkEndDate] [nvarchar](10) NULL,
    [jobStateID] [int] NULL,
    [RegisterType] [int] NULL,
    [RegisterState] [int] NULL,
    [En_time] [datetime] NULL,
    [Fa_time] [nvarchar](40) NULL,
    [Status] [nvarchar](100) NULL,
    [PortalId] [int] NULL,
    [ModuleId] [int] NULL,
    [UserId] [int] NULL,
    [BrName] [nvarchar](150) NULL,
    [BrCode] [nvarchar](20) NULL,
    [WorkEndDate_New] [nvarchar](10) NULL
) ON [PRIMARY]
insert into #tblTemp
select * from [dbo].[Shora.Personel_Branch_Copy] 
        where WorkStartDate is not null 
        --and [dbo].[ShamsiToMiladi](WorkStartDate) <GETDATE() 
        --and [dbo].[ShamsiToMiladi](WorkEndDate) <GETDATE() 
        and PID=@PID
        --and [dbo].[ShamsiToMiladi](WorkEndDate)<[dbo].[ShamsiToMiladi](@NewDate)
        order by WorkStartDate
DECLARE Events CURSOR FOR
    SELECT [dbo].[ShamsiToMiladi](WorkStartDate) AS StartDate,[dbo].[ShamsiToMiladi](WorkEndDate) AS EndDate
        FROM #tblTemp        
    ORDER BY StartDate;
--drop table #tblTemp
    DECLARE @SDate date,
            @EDate date,
            @Period_Start date,
            @Period_End date,
            @Total int,
            @OldSDate date,
            @OldEDate date

    OPEN Events;
    FETCH NEXT FROM Events
    INTO @SDate, @EDate;
    set @Total=0
    SET @Period_Start =@SDate
    set @Period_End=@EDate
    WHILE @@FETCH_STATUS = 0
    BEGIN      
    if @OldSDate>@Period_End
        begin
            set @Period_Start=@SDate            
            if @Period_End>=@Period_Start
            set @Total+=DATEDIFF(DAY,@Period_Start,@Period_End)
        end
    else if @SDate<@Period_End
        begin       
        set @Period_Start=@Period_Start     
            set @Total=DATEDIFF(DAY,@Period_Start,@Period_End)
        end
        set @OldSDate=@SDate 
        set @OldEDate=@EDate
        FETCH NEXT FROM Events
        INTO @SDate, @EDate;
        if  @Period_End<@EDate
        set @Period_End=@EDate
    END;
INSERT INTO [dbo].[PersonelDays]
           (PID
           ,[Total_Start]
           ,[Total_End]
           ,[Total_count])
     VALUES
           (@PID,           
            @Period_Start,
            @Period_End,
            @Total
           )
drop table #tblTemp
CLOSE Events
DEALLOCATE Events
END;