Sequential Date String

I hope this is not a deception of another question, but I could not see it anywhere - it is also a simplified version of another question that I asked , I hope that I will begin to work on how to approach it.

I am looking to work out consistent payment ranges when there is at least one payment in each month.

I have the following data examples

CREATE TABLE #data
(
Contact_reference NVARCHAR(55)
,Date_payment DATETIME
,Payment_value MONEY
)

INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2003-06-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2004-06-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2004-12-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-04-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-05-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-06-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-07-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-08-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-09-08',12.82)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-10-10',12.8205)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-11-10',12.8205)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2005-12-10',12.8205)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2006-01-10',12.8205)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2006-02-10',12.8205)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2006-02-28',12.8205)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2006-04-12',12.8205)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2006-05-10',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2007-06-11',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2007-07-10',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2007-08-09',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2007-09-10',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2007-10-09',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2007-11-09',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2007-12-10',19.2308)
INSERT INTO #data VALUES ('18EC3CD2-3065-4FF4-BE40-000004228590','2008-01-10',19.2308)

And what I would like to do is to develop for each contact the ranges by which they were given sequentially (defined as providing at least once in each calendar month), the number of consecutive payments, the total value for each (and ideally, if possible, the gap between the current range and the end of the very last).

:

CREATE TABLE #results
(
contact_reference NVARCHAR(55)
,Range_start DATETIME
,Range_end DATETIME
,Payments INT
,Value MONEY
,months_until_next_payment INT --works out the gap between the range_end date for a group and the range_start date for the next group
)
INSERT INTO #results VALUES('18EC3CD2-3065-4FF4-BE40-000004228590','2003-06-08','2003-06-08',1,12.82,12)
INSERT INTO #results VALUES('18EC3CD2-3065-4FF4-BE40-000004228590','2004-06-08','2004-06-08',1,12.82,6)
INSERT INTO #results VALUES('18EC3CD2-3065-4FF4-BE40-000004228590','2004-12-08','2004-12-08',1,12.82,4)
INSERT INTO #results VALUES('18EC3CD2-3065-4FF4-BE40-000004228590','2005-04-08','2006-02-28',12,153.843,2)
INSERT INTO #results VALUES('18EC3CD2-3065-4FF4-BE40-000004228590','2006-04-12','2008-06-06',27,416.6673,NULL)

, , , :)

+3
2

: months_until_next_payment. , , , SQL Server .

;WITH base AS ( 
SELECT    Contact_reference  ,
          Payment_value,
          DATEPART(YEAR, Date_payment)*12 + DATEPART(MONTH, Date_payment) - 
               DENSE_RANK() OVER 
                   (PARTITION BY Contact_reference 
                    ORDER BY DATEPART(YEAR, Date_payment)*12 + DATEPART(MONTH, Date_payment)) AS G,
          Date_payment
 FROM     #data
 ),
 cte AS
 (
 SELECT 
          Contact_reference, 
          ROW_NUMBER() over (partition by Contact_reference 
                                 order by MIN(Date_payment)) RN,
          MIN(Date_payment) Range_start,
          MAX(Date_payment) Range_end, 
          COUNT(Payment_value) Payments, 
          SUM(Payment_value) Value
 FROM base
 GROUP BY Contact_reference, G
 )
 SELECT 
       c1.Contact_reference, 
       c1.Payments, 
       c1.Range_end, 
       c1.Range_start, 
       c1.Value, 
       DATEDIFF(month, c1.Range_end,c2.Range_start) months_until_next_payment
 FROM cte c1
 LEFT join cte c2 ON c1.Contact_reference=c2.Contact_reference and c2.RN = c1.RN+1
+4

. , #/java, .

DECLARE @date DATETIME
DECLARE @nextDate DATETIME
DECLARE @rangeStart DATETIME
DECLARE @rangeEnd DATETIME

DECLARE @value decimal(18,2)
DECLARE @valueSum decimal(18,2)
DECLARE @count int

DECLARE @PaymentCursor CURSOR

SET @PaymentCursor = CURSOR FOR
    SELECT Date_payment, Payment_value FROM #data
    ORDER BY Date_payment

OPEN @PaymentCursor
    FETCH NEXT FROM @PaymentCursor INTO @nextDate, @value   
    SET @date = @nextDate
    SET @rangeStart = @nextDate
    SET @valueSum = 0
    SET @count = 0

    WHILE (@@FETCH_STATUS = 0)
    BEGIN       
        FETCH NEXT FROM @PaymentCursor INTO @nextDate, @value

        SET @count = @count + 1
        SET @valueSum = @valueSum + @value      

        IF (DATEDIFF(mm, @date, @nextDate) > 1)
        BEGIN
            SELECT @rangeStart AS RangeStart, @date AS RangeEnd, @count AS Coount, @valueSum AS VALUE, DATEDIFF(mm, @date, @nextDate) AS months_until_next_payment
            SET @valueSum = 0               
            SET @count = 0
            SET @rangeStart = @nextDate
        END

        SET @date = @nextDate           
    END

    SELECT @rangeStart AS RangeStart, @date AS RangeEnd, @count AS Coount, @valueSum AS VALUE, null AS months_until_next_payment

CLOSE @PaymentCursor
DEALLOCATE @PaymentCursor
+1

Source: https://habr.com/ru/post/1766952/


All Articles