SQL Server How to get Date Difference excluding We

Question

I have this table:

tbl_Sales

----------------------------------------
|Item_Code|Sold|Date                   |
|---------+----+-----------------------|
|BBPen100 |30  |2017-04-17 00:00:00.000|
|BBPen100 |21  |2017-04-13 00:00:00.000|
|BBPen100 |13  |2017-04-12 00:00:00.000|
|XSHIRT80 |0   |2017-04-17 00:00:00.000|
|XSHIRT80 |24  |2017-04-14 00:00:00.000|
|XSHIRT80 |9   |2017-04-13 00:00:00.000|
|XSHIRT80 |5   |2017-04-12 00:00:00.000| 
|YBSHADE7 |0   |2017-04-17 00:00:00.000| 
|YBSHADE7 |6   |2017-04-15 00:00:00.000| 
|YBSHADE7 |0   |2017-04-13 00:00:00.000| 
|YBSHADE7 |11  |2017-04-12 00:00:00.000| 
----------------------------------------

How can I get the last non-zero Sold value from the last 2 working days? This means that I need to exclude the Weekends and Holidays. I have this table which consists holidays.

tbl_Holiday

-------------------------
|Holiday_Date           |
|-----------------------|
|2017-04-14 00:00:00.000|
|2017-05-01 00:00:00.000|
|2017-10-18 00:00:00.000|
|2017-12-25 00:00:00.000|
-------------------------

So for example today is 2017-04-18, the output should be like this:

---------------------
|Item_Code|Last_Sold|
|---------+---------|
|BBPen100 |30       |
|XSHIRT80 |9        |
|YBSHADE7 |0        |
---------------------

The goal is to get the last Sold value from LAST 2 working days, so the counting start on 2017-04-17. Output analysis:

BBPen100-since it has value from last 1 working day (2017-04-17), that value will be retrieved.
XSHIRT80-Zero value from last 1 working day (2017-04-17)
        -2017-04-16 & 2017-04-15 are weekends
        -2017-04-14 is holiday
        -So value from 2017-04-13 will be retrieved.
YBSHADE7-Zero value from last 1 working day (2017-04-17)
        -2017-04-16 & 2017-04-15 are weekends
        -2017-04-14 is holiday
        -2017-04-13 has Zero value
        -2017-04-12 is beyond Last 2 working days
        -So value retrived should be Zero

Currently, I have this query:

SELECT Item_Code, Sold AS 'Last_Sold'
FROM tbl_Sales
WHERE CONVERT(date, [DATE]) = CASE
                                WHEN CONVERT(date, [DATE]) = CONVERT(date, DATEADD(day, -1, GETDATE())) THEN CONVERT(date, DATEADD(day, -1, GETDATE()))
                                WHEN CONVERT(date, [DATE]) <> CONVERT(date, DATEADD(day, -1, GETDATE())) THEN CONVERT(date, DATEADD(day, -2, GETDATE()))

But of course, this would not meet the requirements.

Please help me resolve this.

IMPORTANT NOTE: Consider the holidays on weekends and what if I run the program on weekends or holidays.

Thank you in advance.

Answer 1

WITH cte1 AS(
    SELECT t.*
    FROM tbl_Sales t
    LEFT JOIN tbl_Holiday hd
        ON t.Date = hd.Holiday_Date
    WHERE hd.Holiday_Date IS NULL AND
          DATENAME(WEEKDAY, t.Date) <> 'Saturday' AND
          DATENAME(WEEKDAY, t.Date) <> 'Sunday'
),
WITH cte2 AS (
    SELECT *,
           ROW_NUMBER() OVER (PARTITION BY Item_Code ORDER BY Date DESC) rn
    FROM cte1
)
SELECT *
FROM cte2
WHERE rn=1

Answer 2

You could try it

Sample data

DECLARE @SampleData as TABLE (Item_Code varchar(10), Sold int, Date datetime)
Insert into @SampleData VALUES
('BBPen100', 30,'2017-04-17 00:00:00.000'),
('BBPen100', 21,'2017-04-13 00:00:00.000'),
('BBPen100', 13,'2017-04-12 00:00:00.000'),
('XSHIRT80', 0 ,'2017-04-17 00:00:00.000'),
('XSHIRT80', 24,'2017-04-14 00:00:00.000'),
('XSHIRT80', 9 ,'2017-04-13 00:00:00.000'),
('XSHIRT80', 5 ,'2017-04-12 00:00:00.000'),
('YBSHADE7', 0 ,'2017-04-17 00:00:00.000'),
('YBSHADE7', 6 ,'2017-04-15 00:00:00.000'),
('YBSHADE7', 0 ,'2017-04-13 00:00:00.000'),
('YBSHADE7', 11,'2017-04-12 00:00:00.000')

DECLARE @TblHoliday AS TABLE
(
   Holiday_Date date
)

INSERT INTO @TblHoliday
VALUES
('2017-04-14 00:00:00.000'),
('2017-05-01 00:00:00.000'),
('2017-10-18 00:00:00.000'),
('2017-12-25 00:00:00.000')

DECLARE @CurrentDate datetime = '2017-04-18 00:00:00'

You could calculate @2PreviousWorkingDays before @CurrentDate

-- 2 Previous Working Day with out Holiday
DECLARE @2PreviousWorkingDay date = CASE
                         WHEN datepart(dw,@CurrentDate) IN (2,3) THEN dateadd(day,-4, @CurrentDate)  -- 2 previous working day before monday
                         WHEN datepart(dw,@CurrentDate) IN (1) THEN dateadd(day,-3, @CurrentDate)   -- 2 previous working day before sunday
                         ELSE dateadd(day,-2, @CurrentDate) -- other day week
                       END
-- with holiday
SELECT @2PreviousWorkingDay = dateadd(day,0 - (SELECT count(1) FROM @TblHoliday th 
                      WHERE  th.Holiday_Date BETWEEN @2PreviousWorkingDay AND @CurrentDate
                      ANd datepart(dw,th.Holiday_Date) NOT IN (7,1) -- calculate only holiday that isn't weekend
                            )                            
                      , @2PreviousWorkingDay    

And your desired result:

;with temps AS
(
SELECT *, row_number() over(PARTITION BY sd.Item_Code ORDER BY sd.[Date] DESC) AS Rn
FROM @SampleData sd
WHERE sd.[Date] >= @2PreviousWorkingDay -- 2 working days
   AND NOT EXISTS (SELECT 1 FROM @TblHoliday th WHERE th.Holiday_Date = Cast(sd.[Date] AS date)) -- not holiday
   AND datepart(dw,sd.[Date]) NOT IN (7,1) -- not weekend
   AND sd.Sold <> 0 -- not zero sold
)
SELECT sd.Item_Code, ISNULL(t.Sold,0) AS Sold FROM
(
   SELECT DISTINCT sd.Item_Code FROM @SampleData sd
) sd
LEFT JOIN temps t ON t.Item_Code = sd.Item_Code AND t.Rn = 1

Demo link: Rextester