Sql Date Grouping with avaliable dates in database

Question

ID         dateandtime  EmailID
73  6/8/2014 00:00:00   2
74  6/9/2014 00:00:00   2
75  6/10/2014 00:00:00  2
76  6/11/2014 00:00:00  2
77  6/12/2014 00:00:00  2
78  6/13         


        

Answer 1

This will do the trick for you. First identify the range starts and then the range ends and at the same time set a range identity. Last merge the range start and end sets.

DECLARE @Data TABLE (
    [ID] INT,
    [Date] DATE,
    [EmailID] INT
)
INSERT INTO
    @Data
VALUES
    (  73, '2014-06-08', 2 ),
    (  74, '2014-06-09', 2 ),
    (  75, '2014-06-10', 2 ),
    (  76, '2014-06-11', 2 ),
    (  77, '2014-06-12', 2 ),
    (  78, '2014-06-13', 2 ),
    (  79, '2014-06-14', 2 ),
    (  80, '2014-06-16', 2 ),
    (  81, '2014-06-17', 4 ),
    (  82, '2014-06-18', 4 ),
    (  83, '2014-06-19', 4 ),
    (  84, '2014-06-20', 4 ),
    (  89, '2014-06-27', 4 ),
    (  90, '2014-06-28', 4 ),
    (  91, '2014-06-29', 4 ),
    (  92, '2014-06-30', 4 ),
    (  93, '2014-06-01', 4 ),
    (  94, '2014-06-02', 4 ),
    (  95, '2014-06-03', 2 ),
    (  96, '2014-06-04', 2 ),
    (  97, '2014-06-05', 2 ),
    (  98, '2014-06-06', 2 ),
    (  99, '2014-06-07', 2 ),
    ( 100, '2014-06-21', 4 ),
    ( 101, '2014-06-22', 4 ),
    ( 102, '2014-06-23', 4 ),
    ( 103, '2014-06-24', 4 ),
    ( 104, '2014-07-01', 4 ),
    ( 105, '2014-07-02', 4 ),
    ( 106, '2014-07-03', 4 ),
    ( 121, '2014-07-06', 2 ),
    ( 122, '2014-07-07', 2 ),
    ( 123, '2014-07-08', 2 );

WITH RangeStart AS (
    SELECT
        l.[Date] AS Start,
        l.EmailID AS EmailId,
        ROW_NUMBER() OVER (ORDER BY l.[Date]) AS [RangeId]
    FROM
        @Data as l
        LEFT OUTER JOIN @Data as r on r.[Date] = DATEADD(day, -1, l.[Date])
            AND r.EmailID = l.EmailID
    WHERE
        r.[Date] IS NULL
), RangeEnd AS (
    SELECT
        l.[Date] AS [End],
        l.EmailID AS EmailId,
        ROW_NUMBER() OVER (ORDER BY l.[Date]) AS [RangeId]
    FROM
        @Data as l
        LEFT OUTER JOIN @Data as r on r.[Date] = DATEADD(day, +1, l.[Date])
            AND r.EmailID = l.EmailID
    WHERE
        r.[Date] IS NULL
)
SELECT
    RangeStart.Start,
    RangeEnd.[End],
    RangeStart.EmailId
FROM
    RangeStart
    JOIN RangeEnd ON RangeEnd.RangeId = RangeStart.RangeId

The result is not as you might expect, however from what I can se correct.