Count Number of Saturdays in a date range - SQL - sql-server

Question

I have a report which looks for orders during a given date range... It returns the DateName from the report to give me mondays, it then gives me times from the report, to give me 859 for 08:59 for example.. I then use a case on this report to do the following...
WHEN (DATENAME(DW,T1.DocDate)) = 'Monday' AND T1.DocTime >= '700' AND T1.DocTime <= '859' THEN '1 Monday 07:00-08:59'
What I want to achieve, is the count for "1 Monday 07:00-08:59" to be divided by 2 if there has been 2 mondays, divided by 3 if there has been 3 mondays etc... but I have to be able to have it divide by 3 mondays for example, but 2 wednesdays if the date is a tuesday...
The report currently gives a Total of all orders placed in a datetime grouped together but has no division to average for each day.
SELECT (DATENAME(DW, T1.DocDate)) AS Weekday,
T1.DocTime AS Time,
SUM(T1.DocTotal) AS Value,
CASE
WHEN (DATENAME(DW, T1.DocDate)) = 'Monday'
AND T1.DocTime >= '700'
AND T1.DocTime <= '859' THEN '1 Monday 07:00-08:59'
FROM ORDR T1
INNER JOIN OCRD T0 ON T0.CardCode = T1.CardCode
WHERE (T1.DocDate >= #Start
AND T1.DocDate <= #End)
AND T0.QryGroup20 = 'Y'
AND T1.Canceled = 'N'
GROUP BY T1.DocTime,
T1.DocDate;
I expect the report to count the mondays / tuesdays etc that occur between #START and #END to give me an average sale per day and time.Then be able to then somehow divide by the count of the defined days in the case statement. (I'll hopefully be doing this part in Crystal Reports) but if i can get the first part, I'll work on the second half.

Answer 1

Just cross join the DW_Count subquery, which returns the count of every weekday in your orders range. Then you can count your avg for each weekday
SELECT (DATENAME(DW, T1.DocDate)) AS Weekday,
T1.DocTime AS Time,
SUM(T1.DocTotal) AS Value,
SUM(T1.DocTotal)/(CASE WHEN DATENAME(DW, T1.DocDate) = 'Monday' then DW_Count.MonCount
WHEN DATENAME(DW, T1.DocDate) = 'Tuesday' then DW_Count.TueCount
WHEN DATENAME(DW, T1.DocDate) = 'Wednesday' then DW_Count.WedCount
WHEN DATENAME(DW, T1.DocDate) = 'Thursday' then DW_Count.ThuCount
WHEN DATENAME(DW, T1.DocDate) = 'Friday' then DW_Count.FriCount
WHEN DATENAME(DW, T1.DocDate) = 'Saturday' then DW_Count.SatCount
WHEN DATENAME(DW, T1.DocDate) = 'Sunday' then DW_Count.SunCount) AS AvgValue
CASE
WHEN (DATENAME(DW, T1.DocDate)) = 'Monday'
AND T1.DocTime >= '700'
AND T1.DocTime <= '859' THEN '1 Monday 07:00-08:59'
FROM ORDR T1
INNER JOIN OCRD T0 ON T0.CardCode = T1.CardCode
CROSS JOIN (select sum(case when DATENAME(DW, DW_Count.DateValue) = 'Monday' then 1 else 0 end) as MonCount,
sum(case when DATENAME(DW, DW_Count.DateValue) = 'Tuesday' then 1 else 0 end) as TueCount,
sum(case when DATENAME(DW, DW_Count.DateValue) = 'Wednesday' then 1 else 0 end) as WedCount,
sum(case when DATENAME(DW, DW_Count.DateValue) = 'Thursday' then 1 else 0 end) as ThuCount,
sum(case when DATENAME(DW, DW_Count.DateValue) = 'Friday' then 1 else 0 end) as FriCount,
sum(case when DATENAME(DW, DW_Count.DateValue) = 'Saturday' then 1 else 0 end) as SatCount,
sum(case when DATENAME(DW, DW_Count.DateValue) = 'Sunday' then 1 else 0 end) as SunCount
from (select distinct DocDate from ORDR where (T1.DocDate >= #Start AND T1.DocDate <= #End))) AS DW_Count
WHERE (T1.DocDate >= #Start
AND T1.DocDate <= #End)
AND T0.QryGroup20 = 'Y'
AND T1.Canceled = 'N'
GROUP BY T1.DocTime,
T1.DocDate;

Answer 2

You can use the below logic-
For MSSQL
DECLARE #DT1 DATE = '20190802'
DECLARE #DT2 DATE = '20190820'
DECLARE #SatCount INT = 0
WHILE #DT1<= #DT2
BEGIN
SET #SatCount = #SatCount + CASE WHEN DATEPART(WeekDay,#DT1) = 7 THEN 1 ELSE 0 END
SET #DT1 = DATEADD(DD,1,#DT1)
END
SELECT #SatCount
Just one more option-
DECLARE #DT1 DATE = '20190802',
#DT2 DATE = '20190920';
SELECT SUM(CASE WHEN DATEPART(WeekDay,Date) = 7 THEN 1 ELSE 0 END)
FROM
(
SELECT TOP (DATEDIFF(DAY, #DT1, #DT2) + 1)
Date = DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, #DT1)
FROM sys.all_objects a
-- A System table just used for creating multiple rows.
CROSS JOIN sys.all_objects b
-- CROSS JOIN will create number of row = original number of row X original number of row.
)A