How to get days (monday ,tuesday.....) between two different dates? - sql

Question

I need to show a report, which will show weekly report for training session.. from Monday to Saturday some time Sunday with the number of participants per day.
i want sql query to complete this task.
eg.
code days mon tues Wed thurs fri sat sun
10001 3 22 22 22 0 0 0 0
10002 5 10 10 10 10 10 0 0 and so on....
Here no. of participants are same for all days of that training session.
Updated Query
.....................my query as per #competent_tech suggestion .........................
CREATE VIEW SessionDOW
AS
SELECT tcapp_id,title,
case when programtype=1 then 'YP' else 'SP' end programtype,
case when NonResidential=2 then 'Res' else 'Non Res.' end nonresidential,duration,
fromdate,TODATE,
Training_Calendar.Participents,
StartDOW = DATEPART(weekday, FromDate) ,
EndDOW = DATEPART(weekday, FromDate)+Duration -1,
weekenddate=DATEPART(d,CONVERT(date,'12-12-2011'))+6
FROM Training_Calendar
GO
select * from sessiondow
CREATE VIEW SessionDays
AS
SELECT SessionDOW.*,
MON = CASE WHEN (2 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 2 + 7) THEN Participents ELSE 0 END ,
TUE = CASE WHEN (3 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 3 + 7) THEN Participents ELSE 0 END ,
WED = CASE WHEN (4 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 4 + 7) THEN Participents ELSE 0 END ,
THURS = CASE WHEN (5 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 5 + 7) THEN Participents ELSE 0 END ,
FRI = CASE WHEN (6 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 6 + 7) THEN Participents ELSE 0 END ,
SAT = CASE WHEN (7 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 0 + 7) THEN Participents ELSE 0 END,
SUN = CASE WHEN (1 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 1 + 7) THEN Participents ELSE 0 END
FROM SessionDOW
GO
SELECT e.*
FROM SessionDays e INNER JOIN Training_Calendar a ON e.tcapp_id = a.TCApp_Id
GROUP BY e.TCApp_Id,e.title,
e.programtype,
e.nonresidential,e.duration,
e.Participents,
e.StartDOW ,
e.EndDOW,sun,MON,tue,wed,thurs,fri,SAT,e.FromDate,e.todate,e.weekenddate
which give me following result
tcapp_id title programtype nonresidential duration fromdate TODATE Participents StartDOW EndDOW weekenddate MON TUE WED THURS FRI SAT SUN
2011-12/CHD-10001 testing SP Res 10 2011-12-05 2011-12-14 60 2 11 18 60 60 60 60 60 60 60
2011-12/CIT-10001 Training of Palak Technical Officer YP Res 2 2011-12-13 2011-12-14 45 3 4 18 0 45 45 0 0 0 0
2011-12/SIRD-10001 Induction Level Training Programme for JE's of MESCT YP Res 4 2011-12-12 2011-12-15 25 2 5 18 25 25 25 25 0 0 0
2011-12/SIUD-10001 Extempore Leadership Skills Workshop SP Non Res. 5 2011-12-14 2011-12-18 35 4 8 18 0 0 35 35 35 35 35
2011-12/SIUD-10002 fdgd YP Res 6 2011-12-15 2011-12-20 80 5 10 18 80 80 0 80 80 80 80
here week start from 12th dec and end to 18th dec but training session start from 5th dec and ends at 14th dec but still next few days(15,16,17,18) showing participants value. please help.

Answer 1

If this is an SQL Server database, then your query would be something along the lines of:
SELECT CODE ,
SUM(1) AS DAYS ,
SUN = SUM(CASE WHEN DATEPART(weekday, TimeStamp) = 0 THEN 1 ELSE 0 END) ,
MON = SUM(CASE WHEN DATEPART(weekday, TimeStamp) = 1 THEN 1 ELSE 0 END) ,
TUE = SUM(CASE WHEN DATEPART(weekday, TimeStamp) = 2 THEN 1 ELSE 0 END) ,
WED = SUM(CASE WHEN DATEPART(weekday, TimeStamp) = 3 THEN 1 ELSE 0 END) ,
THURS = SUM(CASE WHEN DATEPART(weekday, TimeStamp) = 4 THEN 1 ELSE 0 END) ,
FRI = SUM(CASE WHEN DATEPART(weekday, TimeStamp) = 5 THEN 1 ELSE 0 END) ,
SAT = SUM(CASE WHEN DATEPART(weekday, TimeStamp) = 6 THEN 1 ELSE 0 END)
FROM Event
GROUP BY code
Where Timestamp is the name of the column containing the date of the training and Event is the name of the table.
Update
The above query assumes that one record exists in the database for each student for each day they attend a class.
However, if the database design is such that there is one record for the session that specifies a start date and a number of days and another table where attendees are registered for a given session, then the query becomes a bit different.
Assuming the following rough table structure:
CREATE TABLE Sessions
(
code INT NOT NULL IDENTITY(1, 1) ,
date DATETIME NOT NULL ,
DAYS INT NOT NULL ,
PRIMARY KEY (code)
)
CREATE TABLE Attendees
(
id INT NOT NULL IDENTITY(1, 1) ,
code INT NOT NULL ,
NAME NVARCHAR(100)
PRIMARY KEY (id) ,
FOREIGN KEY (code) REFERENCES sessions (code)
)
We first create a view to calculate the start and end day of week (this makes ensuing views easier to understand):
CREATE VIEW SessionDOW
AS
SELECT CODE ,
DAYS ,
StartDOW = DATEPART(weekday, date) ,
EndDOW = DATEPART(weekday, date) + DAYS
FROM Sessions
GO
We then create a view to record 1 for each day of the week that the session is running. Note that this view takes into account a session that spans two weeks:
CREATE VIEW SessionDays
AS
SELECT CODE ,
DAYS ,
SUN = CASE WHEN (0 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 0 + 7) THEN 1 ELSE 0 END ,
MON = CASE WHEN (1 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 1 + 7) THEN 1 ELSE 0 END ,
TUE = CASE WHEN (2 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 2 + 7) THEN 1 ELSE 0 END ,
WED = CASE WHEN (3 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 3 + 7) THEN 1 ELSE 0 END ,
THURS = CASE WHEN (4 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 4 + 7) THEN 1 ELSE 0 END ,
FRI = CASE WHEN (5 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 5 + 7) THEN 1 ELSE 0 END ,
SAT = CASE WHEN (6 BETWEEN StartDOW AND EndDOW) OR (EndDow >= 6 + 7) THEN 1 ELSE 0 END
FROM SessionDOW
GO
Finally, we join the sessiondays count with the students attending each session and add up the values:
SELECT e.CODE ,
MAX(DAYS) AS DAYS ,
SUN = SUM(SUN) ,
MON = SUM(MON) ,
TUE = SUM(TUE) ,
WED = SUM(WED) ,
THURS = SUM(THURS) ,
FRI = SUM(FRI) ,
SAT = SUM(SAT)
FROM SessionDays e INNER JOIN Attendees a ON e.code = a.code
GROUP BY e.code