How to get week date (7days interval) from SQL Server - sql

I have a table tbl_Customer_Reg and columns are
| ID | Cust_Name | Registration_Date
+------+-----------+------------------
| 1001 | Mr. ABC | 2021-03-13
| 1002 | Mr. MNO | 2021-02-03
| 1003 | Mr. QWE | 2021-04-12
| 1004 | Mr. XYZ | 2021-01-17
Customers are subscribed to a weekly plan. That means every week they get a message and renew every week according to Registration_Date. That means Mr. XYZ renew every week 17,24,31 January 2021 and so on.
Now I want to know the current date (2021-08-20) or before what is the week date of Mr. XYZ.


I think you should create table-function (use cross apply in query) which used cursor or CTE or while.
I write a simple with CTE(maxrecursion 200). You can try this:
CREATE OR ALTER FUNCTION dbo.fnGetWeeklyDateWithDate(#date date)
RETURNS #Result TABLE(WeekDate date, Lev int)
AS
begin
;WITH CTE
AS
(
SELECT #date WeekDate, 1 Lev
UNION ALL
SELECT DATEADD( Week, 1, WeekDate), Lev + 1
FROM CTE c
WHERE DATEADD( Week, 1, WeekDate) <= CAST(GETDATE() as date)
AND Lev < 200
)
INSERT INTO #Result
SELECT WeekDate, Lev
FROM CTE
OPTION (maxrecursion 200)
RETURN
END
result:


A little bit of date arithmetic should do the trick:
SELECT *,
LastRenewal = DATEADD(day, DATEDIFF(day, GETDATE(), Registration_Date) % 7, CAST(GETDATE() AS date)),
NextRenewal = DATEADD(day, DATEDIFF(day, GETDATE(), Registration_Date) % 7 + 7, CAST(GETDATE() AS date))
FROM YourTable;

Related

SQL query group by using day startdatetime and end datetime

I have the following table Jobs:
|Id | StartDateTime | EndDateTime
+----+---------------------+----------------------
|1 | 2020-10-20 23:00:00 | 2020-10-21 05:00:00
|2 | 2020-10-21 10:00:00 | 2020-10-21 11:00:00
Note job id 1 spans October 20 and 21.
I am using the following query
SELECT DAY(StartDateTime), COUNT(id)
FROM Job
GROUP BY DAY(StartDateTime)
To get the following output. But the problem I am facing is that day 21 is not including job id 1. Since the job spans two days I want to include it in both days 20 and 21.
Day | TotalJobs
----+----------
20 | 1
21 | 1
I am struggling to get the following expected output:
Day | TotalJobs
----+----------
20 | 1
21 | 2

One method is to generate the days that you want and then count overlaps:
with days as (
select convert(date, min(j.startdatetime)) as startd,
convert(date, max(j.enddatetime)) as endd
from jobs j
union all
select dateadd(day, 1, startd), endd
from days
where startd < endd
)
select days.startd, count(j.id)
from days left join
jobs j
on j.startdatetime < dateadd(day, 1, startd) and
j.enddatetime >= startd
group by days.startd;
Here is a db<>fiddle.

You can first group by with same start and end date and then group by for start and end date having different start and end date
SELECT a.date, SUM(counts) from (
SELECT DAY(StartDateTime) as date, COUNT(id) counts
FROM Table1
WHERE DAY(StartDateTime) = DAY(EndDateTime)
GROUP BY StartDateTime
UNION ALL
SELECT DAY(EndDateTime), COUNT(id)
FROM Table1
WHERE DAY(StartDateTime) != DAY(EndDateTime)
GROUP BY EndDateTime
UNION ALL
SELECT DAY(StartDateTime), COUNT(id)
FROM Table1
WHERE DAY(StartDateTime) != DAY(EndDateTime)
GROUP BY StartDateTime) a
GROUP BY a.date
Here is SQL Fiddle link
SQL Fiddle
Also replace Table1 with Jobs when running over your db context

SQL to get a row for start and end date for each year given a start date and number of years

I have the following data in a SQL table:
+------------------------------------+
| ID YEARS START_DATE |
+------------------------------------+
| ----------- ----------- ---------- |
| 1 5 2020-12-01 |
| 2 8 2020-12-01 |
+------------------------------------+
Trying to create a SQL that would expand the above data and give me a start and end date for each year depending on YEARS and START_DATE from above table. Sample output below:
+-----------------------------------------------+
| ID YEAR DATE_START DATE_END |
+-----------------------------------------------+
| ----------- ----------- ---------- ---------- |
| 1 1 2020-12-01 2021-11-30 |
| 1 2 2021-12-01 2022-11-30 |
| 1 3 2022-12-01 2023-11-30 |
| 1 4 2023-12-01 2024-11-30 |
| 1 5 2024-12-01 2025-11-30 |
| 2 1 2020-12-01 2021-11-30 |
| 2 2 2021-12-01 2022-11-30 |
| 2 3 2022-12-01 2023-11-30 |
| 2 4 2023-12-01 2024-11-30 |
| 2 5 2024-12-01 2025-11-30 |
| 2 6 2025-12-01 2026-11-30 |
| 2 7 2026-12-01 2027-11-30 |
| 2 8 2027-12-01 2028-11-30 |
+-----------------------------------------------+

I would use an inline tally for this, as they are Far faster than a recursive CTE solution. Assuming you have low values for Years:
WITH YourTable AS(
SELECT *
FROM (VALUES(1,5,CONVERT(date,'20201201')),
(2,8,CONVERT(date,'20201201')))V(ID,Years, StartDate))
SELECT ID,
V.I + 1 AS [Year],
DATEADD(YEAR, V.I, YT.StartDate) AS StartDate,
DATEADD(DAY, -1, DATEADD(YEAR, V.I+1, YT.StartDate)) AS EndDate
FROM YourTable YT
JOIN (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9),(10))V(I) ON YT.Years > V.I;
If you have more than 10~ years you can use either create a tally table, or create an large one inline in a CTE. This would start as:
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I --remove the -1 if you don't want to start from 0
FROM N N1, N N2) --100 rows, add more Ns for more rows
...
Of course, I doubt you have 1,000 of years of data.

You can use a recursive CTE:
with cte as (
select id, 1 as year, start_date,
dateadd(day, -1, dateadd(year, 1, start_date)) as end_date,
years as num_years
from t
union all
select id, year + 1, dateadd(year, 1, start_date),
dateadd(day, -1, dateadd(year, 1, start_date)) as end_date,
num_years
from cte
where year < num_years
)
select id, year, start_date, end_date
from cte;
Here is a db<>fiddle.

In a query, you can use the following:
DATEADD(YEAR, 1, DATE_START) - 1
to add this to the table you can just create the extra column, and set it equal to the value of the above, e.g.
UPDATE MyTable
SET DATE_END = DATEADD(YEAR, 1, DATE_START) - 1

If you are working with sql server, then you can try to use operator CROSS APPLY with master.dbo.spt_values table to get list of numbers and generate dates:
select ID,T.number+1 as YEAR,
--generate date_start using T.number
dateadd(year,T.number,START_DATE)date_start,
--generate end_date: adding 1 year to start date
dateadd(dd,-1,dateadd(year,1,dateadd(year,T.number,START_DATE)))date_end
from Table
cross apply
master.dbo.spt_values T
where T.type='P' and T.number<YEARS

SQL how to count census points occurring between date records

I’m using MS-SQL-2008 R2 trying to write a script that calculates the Number of Hospital Beds occupied on any given day, at 2 census points: midnight, and 09:00.
I’m working from a data set of patient Ward Stays. Basically, each row in the table is a record of an individual patient's stay on a single ward, and records the date/time the patient is admitted onto the ward, and the date/time the patient leaves the ward.
A sample of this table is below:
Ward_Stay_Primary_Key | Ward_Start_Date_Time | Ward_End_Date_Time
1 | 2017-09-03 15:04:00.000 | 2017-09-27 16:55:00.000
2 | 2017-09-04 18:08:00.000 | 2017-09-06 18:00:00.000
3 | 2017-09-04 13:00:00.000 | 2017-09-04 22:00:00.000
4 | 2017-09-04 20:54:00.000 | 2017-09-08 14:30:00.000
5 | 2017-09-04 20:52:00.000 | 2017-09-13 11:50:00.000
6 | 2017-09-05 13:32:00.000 | 2017-09-11 14:49:00.000
7 | 2017-09-05 13:17:00.000 | 2017-09-12 21:00:00.000
8 | 2017-09-05 23:11:00.000 | 2017-09-06 17:38:00.000
9 | 2017-09-05 11:35:00.000 | 2017-09-14 16:12:00.000
10 | 2017-09-05 14:05:00.000 | 2017-09-11 16:30:00.000
The key thing to note here is that a patient’s Ward Stay can span any length of time, from a few hours to many days.
The following code enables me to calculate the number of beds at both census points for any given day, by specifying the date in the case statement:
SELECT
'05/09/2017' [Date]
,SUM(case when Ward_Start_Date_Time <= '05/09/2017 00:00:00.000' AND (Ward_End_Date_Time >= '05/09/2017 00:00:00.000' OR Ward_End_Date_Time IS NULL)then 1 else 0 end)[No. Beds Occupied at 00:00]
,SUM(case when Ward_Start_Date_Time <= '05/09/2017 09:00:00.000' AND (Ward_End_Date_Time >= '05/09/2017 09:00:00.000' OR Ward_End_Date_Time IS NULL)then 1 else 0 end)[No. Beds Occupied at 09:00]
FROM
WardStaysTable
And, based on the sample 10 records above, generates this output:
Date | No. Beds Occupied at 00:00 | No. Beds Occupied at 09:00
05/09/2017 | 4 | 4
To perform this for any number of days is obviously onerous, so what I’m looking to create is a query where I can specify a start/end date parameter (e.g. 1st-5th Sept), and for the query to then evaluate the Ward_Start_Date_Time and Ward_End_Date_Time variables for each record, and – grouping by the dates defined in the date parameter – count each time the 00:00:00.000 and 09:00:00.000 census points fall between these 2 variables, to give an output something along these lines (based on the above 10 records):
Date | No. Beds Occupied at 00:00 | No. Beds Occupied at 09:00
01/09/2017 | 0 | 0
02/09/2017 | 0 | 0
03/09/2017 | 0 | 0
04/09/2017 | 1 | 1
05/09/2017 | 4 | 4
I’ve approached this (perhaps naively) thinking that if I use a cte to create a table of dates (defined by the input parameters), along with associated midnight and 9am census date/time points, then I could use these variables to group and evaluate the dataset.
So, this code generates the grouping dates and census date/time points:
DECLARE
#StartDate DATE = '01/09/2017'
,#EndDate DATE = '05/09/2017'
,#0900 INT = 540
SELECT
DATEADD(DAY, nbr - 1, #StartDate) [Date]
,CONVERT(DATETIME,(DATEADD(DAY, nbr - 1, #StartDate))) [MidnightDate]
,DATEADD(mi, #0900,(CONVERT(DATETIME,(DATEADD(DAY, nbr - 1, #StartDate))))) [0900Date]
FROM
(
SELECT
ROW_NUMBER() OVER ( ORDER BY c.object_id ) AS nbr
FROM sys.columns c
) nbrs
WHERE nbr - 1 <= DATEDIFF(DAY, #StartDate, #EndDate)
The stumbling block I’ve hit is how to join the cte to the WardStays dataset, because there’s no appropriate key… I’ve tried a few iterations of using a subquery to make this work, but either I’m taking the wrong approach or I’m getting my syntax in a mess.
In simple terms, the logic I’m trying to create to get the output is something like:
SELECT
[Date]
,SUM (case when WST.Ward_Start_Date_Time <= [MidnightDate] AND (WST.Ward_End_Date_Time >= [MidnightDate] OR WST.Ward_End_Date_Time IS NULL then 1 else 0 end) [No. Beds Occupied at 00:00]
,SUM (case when WST.Ward_Start_Date_Time <= [0900Date] AND (WST.Ward_End_Date_Time >= [0900Date] OR WST.Ward_End_Date_Time IS NULL then 1 else 0 end) [No. Beds Occupied at 09:00]
FROM WardStaysTable WST
GROUP BY [Date]
Is the above somehow possible, or am I barking up the wrong tree and need to take a different approach altogether? Appreciate any advice.

I would expect something like this:
WITH dates as (
SELECT CAST(#StartDate as DATETIME) as dte
UNION ALL
SELECT DATEADD(DAY, 1, dte)
FROM dates
WHERE dte < #EndDate
)
SELECT dates.dte [Date],
SUM(CASE WHEN Ward_Start_Date_Time <= dte AND
Ward_END_Date_Time >= dte
THEN 1 ELSE 0
END) as num_beds_0000,
SUM(CASE WHEN Ward_Start_Date_Time <= dte + CAST('09:00' as DATETIME) AND
Ward_END_Date_Time >= dte + CAST('09:00' as DATETIME)
THEN 1 ELSE 0
END) as num_beds_0900
FROM dates LEFT JOIN
WardStaysTable wt
ON wt.Ward_Start_Date_Time <= DATEADD(day, 1, dates.dte) AND
wt.Ward_END_Date_Time >= dates.dte
GROUP BY dates.dte
ORDER BY dates.dte;
The cte is just creating the list of dates.

What a cool exercise. Here is what I came up with:
CREATE TABLE #tmp (ID int, StartDte datetime, EndDte datetime)
INSERT INTO #tmp values(1,'2017-09-03 15:04:00.000','2017-09-27 06:55:00.000')
INSERT INTO #tmp values(2,'2017-09-04 08:08:00.000','2017-09-06 18:00:00.000')
INSERT INTO #tmp values(3,'2017-09-04 13:00:00.000','2017-09-04 22:00:00.000')
INSERT INTO #tmp values(4,'2017-09-04 20:54:00.000','2017-09-08 14:30:00.000')
INSERT INTO #tmp values(5,'2017-09-04 20:52:00.000','2017-09-13 11:50:00.000')
INSERT INTO #tmp values(6,'2017-09-05 13:32:00.000','2017-09-11 14:49:00.000')
INSERT INTO #tmp values(7,'2017-09-05 13:17:00.000','2017-09-12 21:00:00.000')
INSERT INTO #tmp values(8,'2017-09-05 23:11:00.000','2017-09-06 07:38:00.000')
INSERT INTO #tmp values(9,'2017-09-05 11:35:00.000','2017-09-14 16:12:00.000')
INSERT INTO #tmp values(10,'2017-09-05 14:05:00.000','2017-09-11 16:30:00.000')
DECLARE
#StartDate DATE = '09/01/2017'
,#EndDate DATE = '10/01/2017'
, #nHours INT = 9
;WITH d(OrderDate) AS
(
SELECT DATEADD(DAY, n-1, #StartDate)
FROM (SELECT TOP (DATEDIFF(DAY, #StartDate, #EndDate) + 1)
ROW_NUMBER() OVER (ORDER BY [object_id]) FROM sys.all_objects) AS x(n)
)
, CTE AS(
select OrderDate, t2.*
from #tmp t2
cross apply(select orderdate from d ) d
where StartDte >= #StartDate and EndDte <= #EndDate)
select OrderDate,
SUM(CASE WHEN OrderDate >= StartDte and OrderDate <= EndDte THEN 1 ELSE 0 END) [No. Beds Occupied at 00:00],
SUM(CASE WHEN StartDTE <= DateAdd(hour,#nHours,CAST(OrderDate as datetime)) and DateAdd(hour,#nHours,CAST(OrderDate as datetime)) <= EndDte THEN 1 ELSE 0 END) [No. Beds Occupied at 09:00]
from CTE
GROUP BY OrderDate
This should allow you to check for any hour of the day using the #nHours parameter if you so choose. If you only want to see records that actually fall within your date range then you can filter the cross apply on start and end dates.

Duration overlap causing double counting

I'm using SQL Server Management Studio 2008 for query creation. Reporting Services 2008 for report creation.
I have been trying to work this out over a couple of weeks and I have hit a brick wall. I’m hoping someone will be able to come up with the solution as right now my brain has turned to mush.
I am currently developing an SQL query that will be feeding data through to a Reporting Services report. The aim of the report is to show the percentage of availability for first aid providers within locations around the county we are based in. The idea is that there should be only one first aider providing cover at a time at each of our 20 locations.
This has all been working fine apart from the first aiders at one location have been overlapping their cover at the start and end of each period of cover.
Example of cover overlap:
| Location | start_date | end_date |
+----------+---------------------+---------------------+
| Wick | 22/06/2015 09:00:00 | 22/06/2015 19:00:00 |
| Wick | 22/06/2015 18:30:00 | 23/06/2015 09:00:00 |
| Wick | 23/06/2015 09:00:00 | 23/06/2015 18:30:00 |
| Wick | 23/06/2015 18:00:00 | 24/06/2015 09:00:00 |
+----------+---------------------+---------------------+
In a perfect world the database that they set their cover in wouldn’t allow them to do this but it’s an externally developed database that doesn’t allow us to make changes like that to it. We also aren’t allowed to create functions, stored procedures, tally tables etc…
The query itself should return the number of minutes that each location has had first aid cover for, then broken down into hours of the day. Any overlap in cover shouldn’t end up adding additional cover and should be merged. One person can be on at a time, if they overlap then it should only count as one person lot of cover.
Example Output:
+----------+---------------------+---------------------+----------+--------------+--------+-------+------+----------+
| Location | fromDt | toDt | TimeDiff | Availability | DayN | DayNo | Hour | DayCount |
+----------+---------------------+---------------------+----------+--------------+--------+-------+------+----------+
| WicK | 22/06/2015 18:00:00 | 22/06/2015 18:59:59 | 59 | 100 | Monday | 1 | 18 | 0 |
| WicK | 22/06/2015 18:30:00 | 22/06/2015 18:59:59 | 29 | 50 | Monday | 1 | 18 | 0 |
| WicK | 22/06/2015 19:00:00 | 22/06/2015 19:59:59 | 59 | 100 | Monday | 1 | 19 | 0 |
+----------+---------------------+---------------------+----------+--------------+--------+-------+------+----------+
Example Code:
DECLARE
#StartTime datetime,
#EndTime datetime,
#GivenDate datetime;
SET #GivenDate = '2015-06-22';
SET #StartTime = #GivenDate + ' 00:00:00';
SET #EndTime = '2015-06-23' + ' 23:59:59';
Declare #Sample Table
(
Location Varchar(50),
StartDate Datetime,
EndDate Datetime
)
Insert #Sample
Select
sta.location,
act.Start,
act.END
from emp,
con,
sta,
act
where
emp.ID = con.ID
and con.location = sta.location
and SUBSTRING(sta.ident,3,2) in ('51','22')
and convert(varchar(10),act.start,111) between #GivenDate and #EndTime
and act.ACT= 18
group by sta.location,
act.Start,
act.END
order by 2
;WITH Yak (location, fromDt, toDt, maxDt,hourdiff)
AS (
SELECT location,
StartDate,
/*check if the period of cover rolls onto the next hour */
convert(datetime,convert(varchar(21),
CONVERT(varchar(10),StartDate,111)+' '
+convert(varchar(2),datepart(hour,StartDate))+':59'+':59'))
,
EndDate
,dateadd(hour,1,dateadd(hour, datediff(hour, 0, StartDate), 0))-StartDate
FROM #Sample
UNION ALL
SELECT location,
dateadd(second,1,toDt),
dateadd(hour, 1, toDt),
maxDt,
hourdiff
FROM Yak
WHERE toDt < maxDt
) ,
TAB1 (location, FROMDATE,TODATE1,TODATE) AS
(SELECT
location,
#StartTime,
convert(datetime,convert(varchar(21),
CONVERT(varchar(10),#StartTime,120)+' '
+convert(varchar(2),datepart(hour,#StartTime))+':59'+':59.999')),
#EndTime
from #Sample
UNION ALL
SELECT
location,
(DATEADD(hour, 1,(convert(datetime,convert(varchar(21),
CONVERT(varchar(10),FROMDATE,120)+' '
+convert(varchar(2),datepart(hour,FROMDATE))+':00'+':00.000')))))ToDate,
(DATEADD(hour, 1,(convert(datetime,convert(varchar(21),
CONVERT(varchar(10),TODATE1,120)+' '
+convert(varchar(2),datepart(hour,TODATE1))+':59'+':59.999'))))) Todate1,
TODATE
FROM TAB1 WHERE TODATE1 < TODATE
),
/*CTE Tab2 adds zero values to all possible hours between start and end dates */
TAB2 AS
(SELECT location, FROMDATE,
CASE WHEN TODATE1 > TODATE THEN TODATE ELSE TODATE1 END AS TODATE
FROM TAB1)
SELECT location,
fromDt,
/* Display MaxDT as start time if cover period goes into next dat */
CASE WHEN toDt > maxDt THEN maxDt ELSE toDt END AS toDt,
/* If the end date is on the next day find out the minutes between the start date and the end of the day or find out the minutes between the next day and the end date */
Case When ToDt > Maxdt then datediff(mi,fromDt,maxDt) else datediff(mi,FromDt,ToDt) end as TimeDiff,
Case When ToDt > Maxdt then round(datediff(S,fromDt,maxDt)/3600.0*100,0) else round(datediff(S,FromDt,ToDt)/3600.0*100.0,0) end as Availability,
/*Display the name of the day of the week*/
CASE WHEN toDt > maxDt THEN datename(dw,maxDt) ELSE datename(dw,fromDt) END AS DayN,
CASE WHEN toDt > maxDt THEN case when datepart(dw,maxDt)-1 = 0 then 7 else datepart(dw,maxDt)-1 end ELSE case when datepart(dw,fromDt)-1 = 0 then 7 else datepart(dw,fromDt)-1 END end AS DayNo
,DATEPART(hour, fromDt) as Hour,
'0' as DayCount
FROM Yak
where Case When ToDt > Maxdt then datediff(mi,fromDt,maxDt) else datediff(mi,FromDt,ToDt) end <> 0
group by location,fromDt,maxDt,toDt
Union all
SELECT
tab2.location,
convert(varchar(19),Tab2.FROMDATE,120),
convert(varchar(19),Tab2.TODATE,120),
'0',
'0',
datename(dw,FromDate) DayN,
case when datepart(dw,FromDate)-1 = 0 then 7 else datepart(dw,FromDate)-1 end AS DayNo,
DATEPART(hour, fromDate) as Hour,
COUNT(distinct datename(dw,fromDate))
FROM TAB2
Where datediff(MINUTE,convert(varchar(19),Tab2.FROMDATE,120),convert(varchar(19),Tab2.TODATE,120)) > 0
group by location, TODATE, FROMDATE
Order by 2
option (maxrecursion 0)
I have tried the following forum entries but they haven't worked in my case:
http://forums.teradata.com/forum/general/need-help-merging-consecutive-and-overlapping-date-spans
Checking for time range overlap, the watchman problem [SQL]
Calculate Actual Downtime ignoring overlap in dates/times
Sorry for being so lengthy but I thought I would try to give you as much detail as possible. Any help will be really appreciated. Thank you.

So the solution I came up with uses temp tables, which you can easily change to be CTEs so you can avoid using a stored procedure.
I tried working with window functions to find overlapping records and get the min and max times, the issue is where you have overlap chaining e.g. 09:00 - 09:10, 09:05 - 09:15, 09:11 - 09:20, so all minutes from 09:00 to 09:20 are covered, but it's almost impossible to tell that 09:00 - 09:10 is related to 09:11 - 09:20 without recursing through the results until you get to the bottom of the chain. (Hopefully that makes sense).
So I exploded out all of the date ranges into every minute between the StartDate and EndDate, then you can use the ROW_NUMBER() window function to catch any duplicates, which in turn you can use to see how many different people covered the same minute.
CREATE TABLE dbo.dates
(
Location VARCHAR(64),
StartDate DATETIME,
EndDate DATETIME
);
INSERT INTO dbo.dates VALUES
('Wick','20150622 09:00:00','20150622 19:00:00'),
('Wick','20150622 18:30:00','20150624 09:00:00'),
('Wick','20150623 09:00:00','20150623 18:30:00'),
('Wick','20150623 18:00:00','20150624 09:00:00'),
('Wick','20150630 09:00:00','20150630 09:30:00'),
('Wick','20150630 09:00:00','20150630 09:45:00'),
('Wick','20150630 09:10:00','20150630 09:25:00'),
('Wick','20150630 09:35:00','20150630 09:55:00'),
('Wick','20150630 09:57:00','20150630 10:10:00');
SELECT ROW_NUMBER() OVER (PARTITION BY Location ORDER BY StartDate) [Id],
Location,
StartDate,
EndDate
INTO dbo.overlaps
FROM dbo.dates;
SELECT TOP 10000 N=IDENTITY(INT, 1, 1)
INTO dbo.Num
FROM master.dbo.syscolumns a CROSS JOIN master.dbo.syscolumns b;
SELECT 0 [N] INTO dbo.Numbers;
INSERT INTO dbo.Numbers SELECT * FROM dbo.Num;
SELECT [Location] = raw.Location,
[WorkedDate] = CAST([MinuteWorked] AS DATE),
[DayN] = DATENAME(WEEKDAY, [MinuteWorked]),
[DayNo] = DATEPART(WEEKDAY, [MinuteWorked]) -1,
[Hour] = DATEPART(HOUR, [MinuteWorked]),
[MinutesWorked] = SUM(IIF(raw.[Minutes] = 1, 1, 0)),
[MaxWorkers] = MAX(raw.[Minutes])
FROM
(
SELECT
o.Location,
DATEADD(MINUTE, n.N, StartDate) [MinuteWorked],
ROW_NUMBER() OVER (PARTITION BY o.Location, DATEADD(MINUTE, n.N, StartDate) ORDER BY DATEADD(MINUTE, n.N, StartDate)) [Minutes]
FROM dbo.overlaps o
INNER JOIN dbo.Numbers n ON n.N < DATEDIFF(MINUTE, StartDate, EndDate)
) raw
GROUP BY
raw.Location,
CAST([MinuteWorked] AS DATE),
DATENAME(WEEKDAY, [MinuteWorked]),
DATEPART(WEEKDAY, [MinuteWorked]) - 1,
DATEPART(HOUR, [MinuteWorked])
Here's a subset of the results:
Location WorkedDate DayN DayNo Hour MinutesWorked MaxWorkers
Wick 2015-06-24 Wednesday 3 8 60 2
Wick 2015-06-30 Tuesday 2 9 58 3
Wick 2015-06-30 Tuesday 2 10 10 1
Here's the fiddle

Query to return all the days of a month

This problem is related to this, which has no solution in sight: here
I have a table that shows me all sessions of an area.
This session has a start date.
I need to get all the days of month of the start date of the session by specific area (in this case)
I have this query:
SELECT idArea, idSession, startDate FROM SessionsPerArea WHERE idArea = 1
idArea | idSession | startDate |
1 | 1 | 01-01-2013 |
1 | 2 | 04-01-2013 |
1 | 3 | 07-02-2013 |
And i want something like this:
date | Session |
01-01-2013 | 1 |
02-01-2013 | NULL |
03-01-2013 | NULL |
04-01-2013 | 1 |
........ | |
29-01-2013 | NULL |
30-01-2013 | NULL |
In this case, the table returns me all the days of January.
The second column is the number of sessions that occur on that day, because there may be several sessions on the same day.
Anyone can help me?

Please try:
DECLARE #SessionsPerArea TABLE (idArea INT, idSession INT, startDate DATEtime)
INSERT #SessionsPerArea VALUES (1,1,'2013-01-01')
INSERT #SessionsPerArea VALUES (1,2,'2013-01-04')
INSERT #SessionsPerArea VALUES (1,3,'2013-07-02')
DECLARE #RepMonth as datetime
SET #RepMonth = '01/01/2013';
WITH DayList (DayDate) AS
(
SELECT #RepMonth
UNION ALL
SELECT DATEADD(d, 1, DayDate)
FROM DayList
WHERE (DayDate < DATEADD(d, -1, DATEADD(m, 1, #RepMonth)))
)
SELECT *
FROM DayList t1 left join #SessionsPerArea t2 on t1.DayDate=startDate and t2.idArea = 1

This will work:
DECLARE #SessionsPerArea TABLE (idArea INT, idSession INT, startDate DATE)
INSERT #SessionsPerArea VALUES
(1,1,'2013-01-01'),
(1,2,'2013-01-04'),
(1,3,'2013-07-02')
;WITH t1 AS
(
SELECT startDate
, DATEADD(MONTH, DATEDIFF(MONTH, '1900-01-01', startDate), '1900-01-01') firstInMonth
, DATEADD(DAY, -1, DATEADD(MONTH, DATEDIFF(MONTH, '1900-01-01', startDate) + 1, '1900-01-01')) lastInMonth
, COUNT(*) cnt
FROM #SessionsPerArea
WHERE idArea = 1
GROUP BY
startDate
)
, calendar AS
(
SELECT DISTINCT DATEADD(DAY, c.number, t1.firstInMonth) d
FROM t1
JOIN master..spt_values c ON
type = 'P'
AND DATEADD(DAY, c.number, t1.firstInMonth) BETWEEN t1.firstInMonth AND t1.lastInMonth
)
SELECT d date
, cnt Session
FROM calendar c
LEFT JOIN t1 ON t1.startDate = c.d
It uses simple join on master..spt_values table to generate rows.

Just an example of calendar table. To return data for a month adjust the number of days between < 32, for a year to 365+1. You can calculate the number of days in a month or between start/end dates with query. I'm not sure how to do this in SQL Server. I'm using hardcoded values to display all dates in Jan-2013. You can adjust start and end dates for diff. month or to get start/end dates with queries...:
WITH data(r, start_date) AS
(
SELECT 1 r, date '2012-12-31' start_date FROM any_table --dual in Oracle
UNION ALL
SELECT r+1, date '2013-01-01'+r-1 FROM data WHERE r < 32 -- number of days between start and end date+1
)
SELECT start_date FROM data WHERE r > 1
/
START_DATE
----------
1/1/2013
1/2/2013
1/3/2013
...
...
1/31/2013