Help with joining to date table

Question

There is an existing report that takes two parameters (BeginDate, EndDate) from the user. When a user inputs two date ranges, it produces a result in the LeadTime column of the difference between the two dates.

I need the LeadTime column to only count Monday-Friday in the result. Right now, it's just Subtracting the difference between two Columns (Order Date and Shipment Date) and the difference = LeadTime. I'm trying to figure out how to not count weekend days.

ie: LeadTime = how many weekdays transpired between BeginDate and EndDate.

  (@BeginDate datetime, @EndDate datetime, @PostingGroup varchar(50))

AS

/*
declare @BeginDate datetime = '6/1/2017', 
        @EndDate datetime = '6/30/2017', 
*/

SELECT 
[Order Date],
[Shipment Date],
DATEDIFF(D,[Order Date],[Shipment Date]) AS LeadTime,
CONVERT(varchar,Order_Number) + '-' + CONVERT(VARCHAR,[Line No_]) AS SalesOrder,
[Document Type],
[Bill-to Customer No_] AS BillToCustomerNumber,
[Bill-to Name],
[Ship-to Name],
Item,
[Posting Group],
Quantity,
[Unit Price],
Sales,
--added field [Description] as per Ticket #7860 gpineda 5/29/2019
[Description]
FROM [dbo].[BI_Sales]
join BI_Sales on DateTable.
WHERE Company = 'LLC'
AND [Order Date] BETWEEN @BeginDate AND @EndDate
AND ([Posting Group] = @PostingGroup OR @PostingGroup = 'ALL')
AND [Document Type] <> 'Credit Memo'
AND Line_Type = 'Item'
AND DATEDIFF(D,[Order Date],[Shipment Date]) <= 7
AND Order_Number <> ''
ORDER BY 5

My DateTable looks like this:

CREATE TABLE    [dbo].[DimDate]
    (   [DateKey] INT primary key, 
        [Date] DATETIME,
        [FullDateUK] CHAR(10), -- Date in dd-MM-yyyy format
        [FullDateUSA] CHAR(10),-- Date in MM-dd-yyyy format
        [DayOfMonth] VARCHAR(2), -- Field will hold day number of Month
        [DaySuffix] VARCHAR(4), -- Apply suffix as 1st, 2nd ,3rd etc
        [DayName] VARCHAR(9), -- Contains name of the day, Sunday, Monday 
        [DayOfWeekUSA] CHAR(1),-- First Day Sunday=1 and Saturday=7
        [DayOfWeekUK] CHAR(1),-- First Day Monday=1 and Sunday=7
        [DayOfWeekInMonth] VARCHAR(2), --1st Monday or 2nd Monday in Month
        [DayOfWeekInYear] VARCHAR(2),
        [DayOfQuarter] VARCHAR(3),
        [DayOfYear] VARCHAR(3),
        [WeekOfMonth] VARCHAR(1),-- Week Number of Month 
        [WeekOfQuarter] VARCHAR(2), --Week Number of the Quarter
        [WeekOfYear] VARCHAR(2),--Week Number of the Year
        [Month] VARCHAR(2), --Number of the Month 1 to 12
        [MonthName] VARCHAR(9),--January, February etc
        [MonthOfQuarter] VARCHAR(2),-- Month Number belongs to Quarter
        [Quarter] CHAR(1),
        [QuarterName] VARCHAR(9),--First,Second..
        [Year] CHAR(4),-- Year value of Date stored in Row
        [YearName] CHAR(7), --CY 2012,CY 2013
        [MonthYear] CHAR(10), --Jan-2013,Feb-2013
        [MMYYYY] CHAR(6),
        [FirstDayOfMonth] DATE,
        [LastDayOfMonth] DATE,
        [FirstDayOfQuarter] DATE,
        [LastDayOfQuarter] DATE,
        [FirstDayOfYear] DATE,
        [LastDayOfYear] DATE,
        [IsHolidayUSA] BIT,-- Flag 1=National Holiday, 0-No National Holiday
        [IsWeekday] BIT,-- 0=Week End ,1=Week Day
        [HolidayUSA] VARCHAR(50),--Name of Holiday in US
        [IsHolidayUK] BIT Null,-- Flag 1=National Holiday, 0-No National Holiday
        [HolidayUK] VARCHAR(50) Null --Name of Holiday in UK
    )
GO



/********************************************************************************************/
--Specify Start Date and End date here
--Value of Start Date Must be Less than Your End Date 

DECLARE @StartDate DATETIME = '01/01/2015' --Starting value of Date Range
DECLARE @EndDate DATETIME = '01/01/2030' --End Value of Date Range

--Temporary Variables To Hold the Values During Processing of Each Date of Year
DECLARE
    @DayOfWeekInMonth INT,
    @DayOfWeekInYear INT,
    @DayOfQuarter INT,
    @WeekOfMonth INT,
    @CurrentYear INT,
    @CurrentMonth INT,
    @CurrentQuarter INT

/*Table Data type to store the day of week count for the month and year*/
DECLARE @DayOfWeek TABLE (DOW INT, MonthCount INT, QuarterCount INT, YearCount INT)

INSERT INTO @DayOfWeek VALUES (1, 0, 0, 0)
INSERT INTO @DayOfWeek VALUES (2, 0, 0, 0)
INSERT INTO @DayOfWeek VALUES (3, 0, 0, 0)
INSERT INTO @DayOfWeek VALUES (4, 0, 0, 0)
INSERT INTO @DayOfWeek VALUES (5, 0, 0, 0)
INSERT INTO @DayOfWeek VALUES (6, 0, 0, 0)
INSERT INTO @DayOfWeek VALUES (7, 0, 0, 0)

--Extract and assign various parts of Values from Current Date to Variable

DECLARE @CurrentDate AS DATETIME = @StartDate
SET @CurrentMonth = DATEPART(MM, @CurrentDate)
SET @CurrentYear = DATEPART(YY, @CurrentDate)
SET @CurrentQuarter = DATEPART(QQ, @CurrentDate)

/********************************************************************************************/
--Proceed only if Start Date(Current date ) is less than End date you specified above

WHILE @CurrentDate < @EndDate
BEGIN

/*Begin day of week logic*/

         /*Check for Change in Month of the Current date if Month changed then 
          Change variable value*/
    IF @CurrentMonth != DATEPART(MM, @CurrentDate) 
    BEGIN
        UPDATE @DayOfWeek
        SET MonthCount = 0
        SET @CurrentMonth = DATEPART(MM, @CurrentDate)
    END

        /* Check for Change in Quarter of the Current date if Quarter changed then change 
         Variable value*/

    IF @CurrentQuarter != DATEPART(QQ, @CurrentDate)
    BEGIN
        UPDATE @DayOfWeek
        SET QuarterCount = 0
        SET @CurrentQuarter = DATEPART(QQ, @CurrentDate)
    END

        /* Check for Change in Year of the Current date if Year changed then change 
         Variable value*/


    IF @CurrentYear != DATEPART(YY, @CurrentDate)
    BEGIN
        UPDATE @DayOfWeek
        SET YearCount = 0
        SET @CurrentYear = DATEPART(YY, @CurrentDate)
    END

        -- Set values in table data type created above from variables 

    UPDATE @DayOfWeek
    SET 
        MonthCount = MonthCount + 1,
        QuarterCount = QuarterCount + 1,
        YearCount = YearCount + 1
    WHERE DOW = DATEPART(DW, @CurrentDate)

    SELECT
        @DayOfWeekInMonth = MonthCount,
        @DayOfQuarter = QuarterCount,
        @DayOfWeekInYear = YearCount
    FROM @DayOfWeek
    WHERE DOW = DATEPART(DW, @CurrentDate)

/*End day of week logic*/


/* Populate Your Dimension Table with values*/

    INSERT INTO [dbo].[DimDate]
    SELECT

        CONVERT (char(8),@CurrentDate,112) as DateKey,
        @CurrentDate AS Date,
        CONVERT (char(10),@CurrentDate,103) as FullDateUK,
        CONVERT (char(10),@CurrentDate,101) as FullDateUSA,
        DATEPART(DD, @CurrentDate) AS DayOfMonth,
        --Apply Suffix values like 1st, 2nd 3rd etc..
        CASE 
            WHEN DATEPART(DD,@CurrentDate) IN (11,12,13) 
            THEN CAST(DATEPART(DD,@CurrentDate) AS VARCHAR) + 'th'
            WHEN RIGHT(DATEPART(DD,@CurrentDate),1) = 1 
            THEN CAST(DATEPART(DD,@CurrentDate) AS VARCHAR) + 'st'
            WHEN RIGHT(DATEPART(DD,@CurrentDate),1) = 2 
            THEN CAST(DATEPART(DD,@CurrentDate) AS VARCHAR) + 'nd'
            WHEN RIGHT(DATEPART(DD,@CurrentDate),1) = 3 
            THEN CAST(DATEPART(DD,@CurrentDate) AS VARCHAR) + 'rd'
            ELSE CAST(DATEPART(DD,@CurrentDate) AS VARCHAR) + 'th' 
            END AS DaySuffix,

        DATENAME(DW, @CurrentDate) AS DayName,
        DATEPART(DW, @CurrentDate) AS DayOfWeekUSA,

        -- check for day of week as Per US and change it as per UK format 
        CASE DATEPART(DW, @CurrentDate)
            WHEN 1 THEN 7
            WHEN 2 THEN 1
            WHEN 3 THEN 2
            WHEN 4 THEN 3
            WHEN 5 THEN 4
            WHEN 6 THEN 5
            WHEN 7 THEN 6
            END 
            AS DayOfWeekUK,

        @DayOfWeekInMonth AS DayOfWeekInMonth,
        @DayOfWeekInYear AS DayOfWeekInYear,
        @DayOfQuarter AS DayOfQuarter,
        DATEPART(DY, @CurrentDate) AS DayOfYear,
        DATEPART(WW, @CurrentDate) + 1 - DATEPART(WW, CONVERT(VARCHAR, 
        DATEPART(MM, @CurrentDate)) + '/1/' + CONVERT(VARCHAR, 
        DATEPART(YY, @CurrentDate))) AS WeekOfMonth,
        (DATEDIFF(DD, DATEADD(QQ, DATEDIFF(QQ, 0, @CurrentDate), 0), 
        @CurrentDate) / 7) + 1 AS WeekOfQuarter,
        DATEPART(WW, @CurrentDate) AS WeekOfYear,
        DATEPART(MM, @CurrentDate) AS Month,
        DATENAME(MM, @CurrentDate) AS MonthName,
        CASE
            WHEN DATEPART(MM, @CurrentDate) IN (1, 4, 7, 10) THEN 1
            WHEN DATEPART(MM, @CurrentDate) IN (2, 5, 8, 11) THEN 2
            WHEN DATEPART(MM, @CurrentDate) IN (3, 6, 9, 12) THEN 3
            END AS MonthOfQuarter,
        DATEPART(QQ, @CurrentDate) AS Quarter,
        CASE DATEPART(QQ, @CurrentDate)
            WHEN 1 THEN 'First'
            WHEN 2 THEN 'Second'
            WHEN 3 THEN 'Third'
            WHEN 4 THEN 'Fourth'
            END AS QuarterName,
        DATEPART(YEAR, @CurrentDate) AS Year,
        'CY ' + CONVERT(VARCHAR, DATEPART(YEAR, @CurrentDate)) AS YearName,
        LEFT(DATENAME(MM, @CurrentDate), 3) + '-' + CONVERT(VARCHAR, 
        DATEPART(YY, @CurrentDate)) AS MonthYear,
        RIGHT('0' + CONVERT(VARCHAR, DATEPART(MM, @CurrentDate)),2) + 
        CONVERT(VARCHAR, DATEPART(YY, @CurrentDate)) AS MMYYYY,
        CONVERT(DATETIME, CONVERT(DATE, DATEADD(DD, - (DATEPART(DD, 
        @CurrentDate) - 1), @CurrentDate))) AS FirstDayOfMonth,
        CONVERT(DATETIME, CONVERT(DATE, DATEADD(DD, - (DATEPART(DD, 
        (DATEADD(MM, 1, @CurrentDate)))), DATEADD(MM, 1, 
        @CurrentDate)))) AS LastDayOfMonth,
        DATEADD(QQ, DATEDIFF(QQ, 0, @CurrentDate), 0) AS FirstDayOfQuarter,
        DATEADD(QQ, DATEDIFF(QQ, -1, @CurrentDate), -1) AS LastDayOfQuarter,
        CONVERT(DATETIME, '01/01/' + CONVERT(VARCHAR, DATEPART(YY, 
        @CurrentDate))) AS FirstDayOfYear,
        CONVERT(DATETIME, '12/31/' + CONVERT(VARCHAR, DATEPART(YY, 
        @CurrentDate))) AS LastDayOfYear,
        NULL AS IsHolidayUSA,
        CASE DATEPART(DW, @CurrentDate)
            WHEN 1 THEN 0
            WHEN 2 THEN 1
            WHEN 3 THEN 1
            WHEN 4 THEN 1
            WHEN 5 THEN 1
            WHEN 6 THEN 1
            WHEN 7 THEN 0
            END AS IsWeekday,
        NULL AS HolidayUSA, Null, Null

    SET @CurrentDate = DATEADD(DD, 1, @CurrentDate)
END

Can someone help me with how to join to this table and what it would look like using the report that already exists? Again, I need it to only include business days when comparing the dates between Order Date and Shipment Date.

Any help would be much appreciated.

Answer 1

This db<>fiddle shows a mock-up of two ways to solve this (with some highly simplified tables).

First, you can create a function that calculates the days between the dates with the conditional check against weekends (and holidays in my example). The function simply takes the order and shipment dates as parameters, counts the number of weekends and holidays between those dates and subtracts those from the total number of days between the two dates.

CREATE FUNCTION fnCalculateLeadTime (@StartDate DATETIME, @EndDate DATETIME)
RETURNS INT
AS
BEGIN
  DECLARE @Weekends INT = 0,
    @Holidays INT = 0,
    @LeadTime INT

  SELECT @Weekends = COUNT(*) FROM DimDate WHERE [Date] >= @StartDate AND [Date] <= @EndDate AND [DayOfWeek] IN (1, 7)
  SELECT @Holidays = COUNT(*) FROM DimDate WHERE [Date] >= @StartDate AND [Date] <= @EndDate AND [IsHoliday] = 1

  SELECT @LeadTime = DATEDIFF(DAY, @StartDate, @EndDate)-@Weekends-@Holidays+1

  RETURN(@LeadTime)
END

The second solution uses CROSS APPLY to apply the DimDate values to the BI Sales data and then uses the COUNT aggregation to count the number of days between the dates 9with the same weekend and holiday conditions.

SELECT b.ID, OrderDate, ShipmentDate, COUNT(d.ID) AS LeadTime
FROM BISales b
CROSS APPLY DimDate d
WHERE d.IsHoliday <> 1 
  AND d.DayOfWeek NOT IN (1, 7)
  AND d.[Date] BETWEEN b.OrderDate and b.ShipmentDate
GROUP BY b.ID, OrderDate, ShipmentDate

The second solution will likely perform better than using a UDF, however, as it aggregates the values it may prove more difficult to include in your existing report query.