SQL Server - Consultando más cercano intervalo de fechas

Question

Si tengo una estructura de tabla como la siguiente:

ProductCode Date 
Foo   4/1/2012 
Foo   4/2/2012 
Foo   4/3/2012 
Foo   4/6/2012 
Foo   4/7/2012 
Foo   4/8/2012 
Foo   4/9/2012 
Foo   4/10/2012 
Foo   4/15/2012 
Foo   4/16/2012 
Foo   4/17/2012 

¿Hay alguna forma de consulta para el intervalo de fechas para un determinado ProductCode y Date (suponiendo que los rangos deben ser secuenciales)? En otras palabras, para esta tabla, Foo existe en 3 intervalos de fechas: 4/1-4/3; 4/6-4/10; y 4/15-4/17 y estoy buscando el rango de fechas dado una fecha.

Tenga en cuenta que no tiene Foo de 4/4, 4/5, 4/11, 4/12, 4/13 y 4/14 fecha.

Ejemplos:
ProductCode=Foo, Date=4/2 devolvería 4/1-4/3 porque las entradas son secuenciales.
ProductCode=Foo, Date=4/4 no devolvería nada
ProductCode=Foo, Date=4/7 devolvería 4/6-4/10 porque las entradas son secuenciales.
ProductCode=Foo, Date=4/12 volvería nada
etc.

Answer 1

se podía hacer con un CTE recursiva.

declare @target_date datetime = convert(datetime, '04/07/2012', 101); 

with source_table as (
    select ProductCode, convert(datetime, Date, 101) as Date 
    from (
    values 
    ('Foo', '4/1/2012') 
    ,('Foo', '4/2/2012') 
    ,('Foo', '4/3/2012') 
    ,('Foo', '4/6/2012') 
    ,('Foo', '4/7/2012') 
    ,('Foo', '4/8/2012') 
    ,('Foo', '4/9/2012') 
    ,('Foo', '4/10/2012') 
    ,('Foo', '4/15/2012') 
    ,('Foo', '4/16/2012') 
    ,('Foo', '4/17/2012') 
) foo(ProductCode, Date) 
), 
recursive_date_lower as (
    select Date from source_table where Date = @target_date 

    union all 

    select dateadd(d, -1, r.Date) from recursive_date_lower r where exists (select 0 from source_table s where s.Date = dateadd(d, -1, r.Date)) 
), 
recursive_date_upper as (
    select Date from source_table where Date = @target_date 

    union all 

    select dateadd(d, 1, r.Date) from recursive_date_upper r where exists (select 0 from source_table s where s.Date = dateadd(d, 1, r.Date)) 
) 
select 
    (select min(Date) from recursive_date_lower) as start, 
    (select max(Date) from recursive_date_upper) as finish 

Answer 2

Se inicia un nuevo rango cuando no hay fila para el día anterior. Si está ejecutando SQL Server 2012, puede usar la función de ventana lag para verificar si una fila presenta un nuevo rango. Una vez que sepa qué filas introducen un nuevo rango, puede contar el número de filas principales para asignar un número único a cada rango.

Tener un número de rango le permite encontrar la fecha de inicio y finalización con min y max. Después de eso, es sólo una cuestión de la selección de la fila:

; with IsHead as 
     (
     select ProductCode 
     ,  Date 
     ,  case when lag(Date) over (partition by ProductCode 
        order by Date) = dateadd(day, -1, Date) then 0 
        else 1 end as IsHead 
     from YourTable 
     ) 
,  RangeNumber as 
     (
     select ProductCode 
     ,  Date 
     ,  sum(IsHead) over (partition by ProductCode order by Date) 
        as RangeNr 
     from IsHead 
     ) 
,  Ranges as 
     (
     select * 
     ,  min(Date) over (partition by RangeNr) as RangeStart 
     ,  max(Date) over (partition by RangeNr) as RangeEnd 
     from RangeNumber 
     ) 
select * 
from Ranges 
where ProductCode = 'Bar' 
     and Date = '4/2/2012' 

Example at SQL Fiddle.

Answer 3

Nota: He añadido una segunda solución (no recursiva), que tiene menos lecturas lógicas (mejor rendimiento).

1) Se puede usar un recursive CTE (demo here):

DECLARE @Test TABLE 
(
    ID   INT IDENTITY NOT NULL UNIQUE, --ID is for insert order 
    ProductCode VARCHAR(10) NOT NULL, 
    [Date]  SMALLDATETIME NOT NULL, 
    PRIMARY KEY(ProductCode, [Date]) 
); 

INSERT @Test (ProductCode , [Date]) 
      SELECT 'Foo' , '20120401' 
UNION ALL SELECT 'Foo' , '20120402' 
UNION ALL SELECT 'Foo' , '20120403' 

UNION ALL SELECT 'Foo' , '20120404' 
--UNION ALL SELECT 'Foo' , '20120405' 

UNION ALL SELECT 'Foo' , '20120406' 
UNION ALL SELECT 'Foo' , '20120407' 
UNION ALL SELECT 'Foo' , '20120408' 
UNION ALL SELECT 'Foo' , '20120409' 
UNION ALL SELECT 'Foo' , '20120410' 
UNION ALL SELECT 'Foo' , '20120415' 
UNION ALL SELECT 'Foo' , '20120416' 
UNION ALL SELECT 'Foo' , '20120417'; 

DECLARE @MyProductCode VARCHAR(10), 
     @MyDate SMALLDATETIME; 


SELECT @MyProductCode = 'Foo', 
     @MyDate = '20120402'; 

WITH CteRecursive 
AS 
(
     --Starting row 
     SELECT t.ID, 
       t.ProductCode, 
       t.[Date], 
       1 AS RowType 
     FROM @Test t 
     WHERE t.ProductCode = @MyProductCode 
     AND  t.[Date] = @MyDate 
     UNION ALL 
     --Add the next days DATEADD(DAY, +1, ..) 
     SELECT crt.ID, 
       crt.ProductCode, 
       crt.[Date], 
       2 AS RowType 
     FROM CteRecursive prev 
     INNER JOIN @Test crt ON DATEADD(DAY, 1, prev.[Date]) = crt.[Date] AND prev.RowType IN (1,2) 
     UNION ALL 
     --Add the previous days DATEADD(DAY, -1, ..) 
     SELECT crt.ID, 
       crt.ProductCode, 
       crt.[Date], 
       0 AS RowType 
     FROM CteRecursive prev 
     INNER JOIN @Test crt ON DATEADD(DAY, -1, prev.[Date]) = crt.[Date] AND prev.RowType IN (0,1) 
) 
SELECT * 
FROM CteRecursive r 
ORDER BY r.[Date] 
/*--Or 
SELECT MIN(r.[Date]) AS BeginDate, MAX(r.[Date]) AS EndDate 
FROM CteRecursive r 
*/ 

Resultados:

ID   ProductCode Date     RowType 
----------- ----------- ----------------------- ------- 
1   Foo   2012-04-01 00:00:00  0 
2   Foo   2012-04-02 00:00:00  1 
3   Foo   2012-04-03 00:00:00  2 
4   Foo   2012-04-04 00:00:00  2 

2) solución no recursiva:

DECLARE @Test TABLE 
(
    ProductCode VARCHAR(10) NOT NULL, 
    [Date]  SMALLDATETIME NOT NULL, 
    PRIMARY KEY(ProductCode, [Date]) 
); 

INSERT @Test (ProductCode , [Date]) 
      SELECT 'Foo' , '20120401' 
UNION ALL SELECT 'Foo' , '20120402' 
UNION ALL SELECT 'Foo' , '20120403' 

UNION ALL SELECT 'Foo' , '20120404' 
--UNION ALL SELECT 'Foo' , '20120405' 

UNION ALL SELECT 'Foo' , '20120406' 
UNION ALL SELECT 'Foo' , '20120407' 
UNION ALL SELECT 'Foo' , '20120408' 
UNION ALL SELECT 'Foo' , '20120409' 
UNION ALL SELECT 'Foo' , '20120410' 
UNION ALL SELECT 'Foo' , '20120415' 
UNION ALL SELECT 'Foo' , '20120416' 
UNION ALL SELECT 'Foo' , '20120417'; 

DECLARE @MyProductCode VARCHAR(10), 
     @MyDate SMALLDATETIME; 


SELECT @MyProductCode = 'Foo', 
     @MyDate = '20120402'; 

DECLARE @StartDate SMALLDATETIME, 
     @EndDate SMALLDATETIME; 

SELECT @EndDate = MAX(b.[Date]) 
FROM  
(
     SELECT a.[Date], 
       ROW_NUMBER() OVER(ORDER BY a.Date ASC)-1 AS RowNum 
     FROM @Test a 
     WHERE a.ProductCode = @MyProductCode 
     AND  a.[Date] >= @MyDate 
) b 
WHERE b.[Date] = DATEADD(DAY, b.RowNum, @MyDate); 

SELECT @StartDate = MIN(b.[Date]) 
FROM  
(
     SELECT a.[Date], 
       ROW_NUMBER() OVER(ORDER BY a.Date DESC)-1 AS RowNum 
     FROM @Test a 
     WHERE a.ProductCode = @MyProductCode 
     AND  a.[Date] <= @MyDate 
) b 
WHERE b.[Date] = DATEADD(DAY, -b.RowNum, @MyDate); 

SELECT @StartDate [@StartDate], @EndDate [@EndDate]; 
SELECT LEFT(CONVERT(VARCHAR(10), @StartDate, 101),5) [@StartDate], LEFT(CONVERT(VARCHAR(10), @EndDate, 101),5) [@EndDate]; 

Resultados:

@StartDate    @EndDate 
----------------------- ----------------------- 
2012-04-01 00:00:00  2012-04-04 00:00:00 

@StartDate @EndDate 
---------- -------- 
04/01  04/04 

Answer 4

Podría haber usado LAG, si SQL Server 2005 lo admitió.Desafortunadamente LAG window function trabajos sobre SQL Server 2012 solamente, y PostgreSQL 8.4 and above ;-)

Obras en SQL Server 2005 supone, SQLFiddle no tiene soporte SQL 2005, trató de SQLFiddle SQL Server 2008 solamente, no 2012:

with DetectLeaders as 
(
    select cr.ProductCode, CurRowDate = cr.Date, PrevRowDate = pr.Date 
    from tbl cr 
    left join tbl pr 
    on pr.ProductCode = cr.ProductCode AND cr.Date = DATEADD(DAY,1,pr.Date) 
), 
MembersLeaders as 
(
    select *, 
     MemberLeader = 
      (select top 1 CurRowDate 
      from DetectLeaders nearest 
      where nearest.PrevRowDate is null 
       and nearest.ProductCode = DetectLeaders.ProductCode 
       and DetectLeaders.CurRowDate >= nearest.CurRowDate 
      order by nearest.CurRowDate desc) 
    from DetectLeaders 
) 
select BeginDate = MIN(CurRowDate), EndDate = MAX(CurRowDate) 
from MembersLeaders 
where MemberLeader = 
    (select MemberLeader 
    from MembersLeaders 
    where ProductCode = 'Foo' and CurRowDate = '4/7/2012') 

prueba en vivo: http://sqlfiddle.com/#!3/3fd1f/1

---

Básicamente esto es como funciona:

PRODUCTCODE  CURROWDATE PREVROWDATE MEMBERLEADER 
Foo    2012-04-01    2012-04-01 
Foo    2012-04-02 2012-04-01 2012-04-01 
Foo    2012-04-03 2012-04-02 2012-04-01 
Foo    2012-04-06    2012-04-06 
Foo    2012-04-07 2012-04-06 2012-04-06 
Foo    2012-04-08 2012-04-07 2012-04-06 
Foo    2012-04-09 2012-04-08 2012-04-06 
Foo    2012-04-10 2012-04-09 2012-04-06 
Foo    2012-04-15    2012-04-15 
Foo    2012-04-16 2012-04-15 2012-04-15 
Foo    2012-04-17 2012-04-16 2012-04-15 
Bar    2012-05-01    2012-05-01 
Bar    2012-05-02 2012-05-01 2012-05-01 
Bar    2012-05-03 2012-05-02 2012-05-01 
Bar    2012-05-06    2012-05-06 
Bar    2012-05-07 2012-05-06 2012-05-06 
Bar    2012-05-08 2012-05-07 2012-05-06 
Bar    2012-05-09 2012-05-08 2012-05-06 
Bar    2012-05-10 2012-05-09 2012-05-06 
Bar    2012-05-15    2012-05-15 
Bar    2012-05-16 2012-05-15 2012-05-15 
Bar    2012-05-17 2012-05-16 2012-05-15 

http://sqlfiddle.com/#!3/35818/11

Answer 5

Usted podría intentar algo como esto (suponiendo SQL Server 2005 +):

WITH partitioned AS (
    SELECT 
    ProductCode, 
    Date, 
    GroupID = DATEDIFF(DAY, 0, Date) 
      - ROW_NUMBER() OVER (PARTITION BY ProductCode ORDER BY Date) 
    FROM atable 
), 
ranges AS (
    SELECT 
    ProductCode, 
    Date, 
    MinDate = MIN(Date) OVER (PARTITION BY ProductCode, GroupID), 
    MaxDate = MAX(Date) OVER (PARTITION BY ProductCode, GroupID) 
    FROM partitioned 
) 
SELECT 
    MinDate, 
    MaxDate 
FROM ranges 
WHERE ProductCode = @ProductCode 
    AND Date = @Date 

Answer 6

También puede utilizar CRUZ APLICAR para encontrar la fecha más cercana:

with DetectLeaders as 
(
    select cr.ProductCode, CurRowDate = cr.Date, PrevRowDate = pr.Date 
    from tbl cr 
    left join tbl pr 
    on pr.ProductCode = cr.ProductCode AND cr.Date = DATEADD(DAY,1,pr.Date) 
), 
MembersLeaders as 
(
    select *  
    from DetectLeaders 
    cross apply(
     select top 1 MemberLeader = CurRowDate 
     from DetectLeaders nearest 
     where nearest.PrevRowDate is null 
      and nearest.ProductCode = DetectLeaders.ProductCode 
      and DetectLeaders.CurRowDate >= nearest.CurRowDate 
     order by nearest.CurRowDate desc 
    ) as xxx 
) 
select BeginDate = MIN(CurRowDate), EndDate = MAX(CurRowDate) 
from MembersLeaders 
where MemberLeader = 
    (select MemberLeader 
    from MembersLeaders 
    where ProductCode = 'Foo' and CurRowDate = '4/7/2012') 

prueba en vivo : http://sqlfiddle.com/#!3/3fd1f/2

---

Básicamente esto es como funciona:

PRODUCTCODE  CURROWDATE PREVROWDATE MEMBERLEADER 
Foo    2012-04-01    2012-04-01 
Foo    2012-04-02 2012-04-01 2012-04-01 
Foo    2012-04-03 2012-04-02 2012-04-01 
Foo    2012-04-06    2012-04-06 
Foo    2012-04-07 2012-04-06 2012-04-06 
Foo    2012-04-08 2012-04-07 2012-04-06 
Foo    2012-04-09 2012-04-08 2012-04-06 
Foo    2012-04-10 2012-04-09 2012-04-06 
Foo    2012-04-15    2012-04-15 
Foo    2012-04-16 2012-04-15 2012-04-15 
Foo    2012-04-17 2012-04-16 2012-04-15 
Bar    2012-05-01    2012-05-01 
Bar    2012-05-02 2012-05-01 2012-05-01 
Bar    2012-05-03 2012-05-02 2012-05-01 
Bar    2012-05-06    2012-05-06 
Bar    2012-05-07 2012-05-06 2012-05-06 
Bar    2012-05-08 2012-05-07 2012-05-06 
Bar    2012-05-09 2012-05-08 2012-05-06 
Bar    2012-05-10 2012-05-09 2012-05-06 
Bar    2012-05-15    2012-05-15 
Bar    2012-05-16 2012-05-15 2012-05-15 
Bar    2012-05-17 2012-05-16 2012-05-15 

http://www.sqlfiddle.com/#!3/3fd1f/3

CROSS APPLY/OUTER APPLY en comparación con JOIN, escalas muy bien también: http://www.ienablemuch.com/2012/04/outer-apply-walkthrough.html