Related
Below is the table I have created and inserted values in it:
CREATE TABLE employees_list
(
employeeID int identity(1,1),
employeeName varchar(25)
)
GO
INSERT INTO employees_list VALUES ('Kevin'),('Charles')
GO
CREATE TABLE hourlyRates
(
employeeID int,
rate int,
rateDate date
)
INSERT INTO hourlyRates VALUES (1, 28, '2016-01-01'),
(1, 39, '2016-02-01'),
(2, 43, '2016-01-01'),
(2, 57, '2016-02-01')
CREATE TABLE workingHours
(
employeeID int,
startdate datetime,
enddate datetime
)
GO
INSERT INTO workingHours VALUES (1, '2016-01-01 09:00', '2016-01-01 17:00'),
(1, '2016-01-02 09:00', '2016-01-02 17:00'),
(1, '2016-02-01 10:00', '2016-02-01 16:00'),
(1, '2016-02-02 11:00', '2016-02-02 13:00'),
(2, '2016-01-01 10:00', '2016-01-01 16:00'),
(2, '2016-01-02 08:00', '2016-01-02 14:00'),
(2, '2016-02-01 14:00', '2016-02-01 19:00'),
(2, '2016-02-02 13:00', '2016-02-02 16:00')
GO
SELECT * FROM employees_list
SELECT * FROM hourlyRates
SELECT * FROM workingHours
Then I ran a query to calculate salaries paid to Employees each month:
SELECT
employeeName,
DATENAME(MONTH, startdate) AS 'Month',
SUM(DATEDIFF(HOUR, startdate, enddate) * rate) AS 'Total Salary'
FROM
hourlyRates, workingHours, employees_list
WHERE
hourlyRates.employeeID = workingHours.employeeID
AND employees_list.employeeID = workingHours.employeeID
AND (hourlyRates.rateDate BETWEEN DATEFROMPARTS(DATEPART(YEAR, workingHours.startDate), DATEPART(MONTH, workingHours.startDate),1)
AND DATEFROMPARTS(DATEPART(YEAR, workingHours.endDate), DATEPART(MONTH, workingHours.endDate),1))
GROUP BY
employeeName, DATENAME(MONTH, startdate)
And I got the following output:
As you can see from the screenshot above that I got the result I wanted.
But the only issue is the month is not being displayed in order.
I tried adding ORDER BY DATENAME(MONTH, startdate) and still the order of month is not being sorted.
I even tried ORDER BY DATEPART(MM, startdate) but it is showing error mentioning that it is not contained in an aggregate function or GROUP BY clause.
What minor change do I need to make in my query ?
Why add ORDER BY DATENAME(MONTH,startdate) not work
Because the ORDER depends on character instead of the month of number.
You can try to add MONTH(startdate) in ORDER BY & GROUP BY, because you might need to add non-aggregate function in GROUP BY
SELECT employeeName,DATENAME(MONTH,startdate) AS 'Month',
SUM(DATEDIFF(HOUR,startdate,enddate) * rate) AS 'Total Salary'
FROM hourlyRates
INNER JOIN workingHours
ON hourlyRates.employeeID = workingHours.employeeID
INNER JOIN employees_list
ON employees_list.employeeID = workingHours.employeeID
WHERE
(hourlyRates.rateDate
BETWEEN DATEFROMPARTS(DATEPART(YEAR, workingHours.startDate), DATEPART(MONTH,workingHours.startDate),1)
AND DATEFROMPARTS(DATEPART(YEAR, workingHours.endDate), DATEPART(MONTH,workingHours.endDate),1))
GROUP BY employeeName,DATENAME(MONTH,startdate),MONTH(startdate)
ORDER BY MONTH(startdate)
sqlfiddle
NOTE
I would use INNER JOIN ANSI syntax instead of , which mean CROSS JOIN because JOIN syntax is generally considered more readable.
As mentioned, ORDER BY DATENAME will sort by the textual name of the month not by the actual ordering of months.
It's best to just group and sort by EOMONTH, then you can pull out the month name from that in the SELECT
Further improvements:
Always use explicit join syntax, not old-style , comma joins.
Give tables short aliases, to make your query more readable.
Your date interval check might not be quite right, and you may need to also adjust the rate caluclation, but I don't know without further info.
A more accurate calculation would probably mean calculating part-dates.
SELECT
e.employeeName,
DATENAME(month, EOMONTH(wh.startdate)) AS Month,
SUM(DATEDIFF(HOUR, wh.startdate, wh.enddate) * hr.rate) AS [Total Salary]
FROM hourlyRates hr
JOIN workingHours wh ON hr.employeeID = wh.employeeID
AND hr.rateDate
BETWEEN DATEFROMPARTS(YEAR(wh.startDate), MONTH(wh.startDate), 1)
AND DATEFROMPARTS(YEAR(wh.endDate), MONTH(wh.endDate), 1)
JOIN employees_list e ON e.employeeID = wh.employeeID
GROUP BY
e.employeeId,
e.employeeName,
EOMONTH(wh.startdate)
ORDER BY
EOMONTH(wh.startdate),
e.employeeName;
db<>fiddle
I have this table and sample data. I want to get the entire month's or specific dates attendance and information like hours he worked or days he was absent.
CREATE TABLE Attendance
(
[EmpCode] int,
[TimeIn] datetime,
[TimeOut] datetime
)
INSERT INTO Attendance VALUES (12, '2018-08-01 09:00:00', '2018-08-01 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-02 09:00:00', '2018-08-02 18:10:00');
INSERT INTO Attendance VALUES (12, '2018-08-03 09:25:00', '2018-08-03 16:56:00');
INSERT INTO Attendance VALUES (12, '2018-08-04 09:13:00', '2018-08-05 18:09:00');
INSERT INTO Attendance VALUES (12, '2018-08-06 09:00:00', '2018-08-07 18:15:00');
INSERT INTO Attendance VALUES (12, '2018-08-07 09:27:00', '2018-08-08 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-08 09:35:00', '2018-08-09 17:21:00');
INSERT INTO Attendance VALUES (12, '2018-08-10 09:00:00', '2018-08-10 17:45:00');
INSERT INTO Attendance VALUES (12, '2018-08-11 09:50:00', '2018-08-11 17:31:00');
INSERT INTO Attendance VALUES (12, '2018-08-13 09:23:00', '2018-08-13 17:19:00');
INSERT INTO Attendance VALUES (12, '2018-08-15 09:21:00', '2018-08-15 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-16 09:00:00', '2018-08-16 17:09:00');
INSERT INTO Attendance VALUES (12, '2018-08-17 09:34:00', '2018-08-17 17:29:00');
INSERT INTO Attendance VALUES (12, '2018-08-18 09:00:00', '2018-08-18 17:10:00');
INSERT INTO Attendance VALUES (12, '2018-08-20 09:34:00', '2018-08-20 17:12:00');
INSERT INTO Attendance VALUES (12, '2018-08-21 09:20:00', '2018-08-21 17:15:00');
INSERT INTO Attendance VALUES (12, '2018-08-22 09:12:00', '2018-08-22 17:19:00');
INSERT INTO Attendance VALUES (12, '2018-08-23 09:05:00', '2018-08-23 17:21:00');
INSERT INTO Attendance VALUES (12, '2018-08-24 09:07:00', '2018-08-24 17:09:00');
INSERT INTO Attendance VALUES (12, '2018-08-25 09:12:00', '2018-08-25 17:05:00');
INSERT INTO Attendance VALUES (12, '2018-08-27 09:21:00', '2018-08-27 17:46:00');
INSERT INTO Attendance VALUES (12, '2018-08-28 09:17:00', '2018-08-28 17:12:00');
INSERT INTO Attendance VALUES (12, '2018-08-29 09:00:00', '2018-08-29 17:36:00');
INSERT INTO Attendance VALUES (12, '2018-08-30 09:12:00', '2018-08-30 17:24:00');
I have a query that tells how many hours employee have worked, but it is only showing days on which data was present in table. I want to show all dates between provided dates and in case there is no data it should NULL in columns.
Here is the query:
SELECT
[EmpCode],
FirstIN = CAST(MIN([TimeIn]) AS TIME),
LastOUT = CAST(MAX([TimeOut]) AS TIME),
CONVERT(VARCHAR(6), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME))/3600)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), (Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 3600) / 60), 2)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 60) , 2 ) AS HoursSpent,
CAST(COALESCE(TimeIn, TimeOut) AS DATE) [Date]
FROM Attendance
WHERE CAST(COALESCE(TimeIn, TimeOut) AS DATE) BETWEEN '2018-08-01' AND '2018-08-25'
GROUP BY EmpCode, TimeIn, TimeOut
For that you need to use recursive way to generate possible dates :
with t as (
select '2018-08-01' as startdt
union all
select dateadd(day, 1, startdt)
from t
where startdt < '2018-08-25'
)
select . . .
from t left join
Attendance at
on cast(coalesce(at.TimeIn, at.TimeOut) as date) = t.startdt;
Just make sure to use date from t instead of Attendance table in SELECT statement.
Note : If you have a large no of date period, then don't forgot to use Query hint OPTION (MAXRECURSION 0), By defalut it has 100 recursion levels.
You May Try Recursive CTE to populate the Dates and Then Join With that to Get the Interval
DECLARE #From DATETIME = '2018-08-01' ,#To DATETIME= '2018-08-25'
;WITH CTE
AS
(
SELECT
[EmpCode] EmpId,
MyDate = #From
FROM Attendance A
UNION ALL
SELECT
EmpId,
MyDate = DATEADD(DAY,1,MyDate)
FROM CTE
WHERE MyDate < #To
)
SELECT
[EmpCode] = CTE.EmpId,
CTE.MyDate,
FirstIN = CAST(MIN([TimeIn]) AS TIME),
LastOUT = CAST(MAX([TimeOut]) AS TIME),
CONVERT(VARCHAR(6), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME))/3600)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), (Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 3600) / 60), 2)
+ ':'
+ RIGHT('0' + CONVERT(VARCHAR(2), Datediff(second, CAST(MIN([TimeIn]) AS TIME), CAST(MAX([TimeOut]) AS TIME)) % 60) , 2 )
AS HoursSpent,
CAST(CTE.MyDate AS DATE) [Date]
FROM CTE
LEFT JOIN Attendance A
ON A.EmpCode = CTE.EmpId
AND CAST(CTE.MyDate AS DATE) = CAST(COALESCE(TimeIn, TimeOut) AS DATE)
GROUP BY CTE.EmpId, TimeIn, TimeOut,CTE.MyDate
ORDER BY 6
A different method, using a Tally Table. The advantage here is that an rCTE is a form of RBAR. The idea of a Tally table isn't as obvious, but is quicker, and also, won't need the OPTION (MAXRECURSION 0) added if you have more than 100 days. in fact, this example handles up to 10,000 days, which shuold be more than enough:
DECLARE #EmpCode int = 12;
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
FROM N N1 --10
CROSS JOIN N N2 --100
CROSS JOIN N N3 --1000
CROSS JOIN N N4 --10000
),
Dates AS(
SELECT DATEADD(DAY, T.I, TT.MinTimeIn) AS CalendarDate,
#EmpCode AS EmpCode
FROM Tally T
CROSS APPLY (SELECT MIN(CONVERT(date,TimeIn)) AS MinTimeIn,
MAX(CONVERT(date,TimeOut)) AS MaxTimeOut
FROM Attendance
WHERE EmpCode = #EmpCode) TT
WHERE DATEADD(DAY, T.I, TT.MinTimeIn) <= CONVERT(date, TT.MaxTimeOut))
SELECT CalendarDate
EmpCode,
TimeIn,
TimeOut
FROM Dates D
LEFT JOIN Attendance A ON D.CalendarDate = CONVERT(date,A.TimeIn)
AND D.EmpCode = A.EmpCode;
How to add values separately by date in order. Suppose there're several values with same date with a particular field. I wamt to sum up those data and want to have a particular row with one date. oredered by date.
So let's say you have some data like this:
DATE VALUE
------------------------------
2017-01-01 100
2017-02-01 50
2017-01-01 75
2017-02-01 25
What it sounds like you want to do is take those 4 rows and combine them down to 2, one for 2017-01-01 and one for 2017-02-01, is that correct?
If so, you just need to do an INSERT with a SELECT and GROUP BY on the origin data.
So if I am trying to INSERT to Test_Table_One and my data was in Origin_Table_One, I would do:
INSERT INTO Test_Table_One
SELECT DATE, SUM(VALUE)
FROM Origin_Table_One
GROUP BY DATE
Does tht make sense?
Try this:
create table #temp
(
Date date,
Sum bigint
)
create table #tempVarious
(
Date date,
value bigint
)
insert into #tempVarious
values
(cast(getdate() as date), 1),
(cast(getdate() as date), 1),
(cast(getdate() as date), 3),
(cast(getdate() as date), 5),
(cast(getdate() as date), 6),
(cast(getdate() as date), 8),
(cast(getdate() as date), 3),
(cast(dateadd(day,-1,getdate()) as date), 1),
(cast(dateadd(day,-1,getdate()) as date), 3),
(cast(dateadd(day,-1,getdate()) as date), 6),
(cast(dateadd(day,-1,getdate()) as date), 2),
(cast(dateadd(day,-1,getdate()) as date), 1)
insert
into #temp
select date
, sum(value)
from #tempVarious
group by date
select *
from #temp
It seems you are very new in SQL, please read these two tutorials about GROUP BY https://www.w3schools.com/sql/sql_groupby.asp and ORDER BY https://www.w3schools.com/sql/sql_orderby.asp
SELECT DATE_COLUMN, SUM(VALUE_COLUM)
FROM TABLE
GROUP BY DATE_COLUMN
ORDER BY DATE_COLUMN
A variant in case you want to order by descending
ORDER BY DATE_COLUMN DESC
In case your column is of type DateTime and you have different times in a single date
SELECT CAST(DATE_COLUMN AS DATE) AS DC, SUM(VALUE_COLUM)
FROM TABLE
GROUP BY CAST(DATE_COLUMN AS DATE)
ORDER BY DC
I have a table like below, What I need that for any particular fund and up to any particular date logic will sum the amount value. Let say I need the sum for 3 dates as 01/28/2015,03/30/2015 and 04/01/2015. Then logic will check for up to first date how many records are there in table . If it found more than one record then it'll sum the amount value. Then for next date it'll sum up to the next date but from the previous date it had summed up.
Id Fund Date Amount
1 A 01/20/2015 250
2 A 02/28/2015 300
3 A 03/20/2015 400
4 A 03/30/2015 200
5 B 04/01/2015 500
6 B 04/01/2015 600
I want result to be like below
Id Fund Date SumOfAmount
1 A 02/28/2015 550
2 A 03/30/2015 600
3 B 04/01/2015 1100
Based on your question, it seems that you want to select a set of dates, and then for each fund and selected date, get the sum of the fund amounts from the selected date to the previous selected date. Here is the result set I think you should be expecting:
Fund Date SumOfAmount
A 2015-02-28 550.00
A 2015-03-30 600.00
B 2015-04-01 1100.00
Here is the code to produce this output:
DECLARE #Dates TABLE
(
SelectedDate DATE PRIMARY KEY
)
INSERT INTO #Dates
VALUES
('02/28/2015')
,('03/30/2015')
,('04/01/2015')
DECLARE #FundAmounts TABLE
(
Id INT PRIMARY KEY
,Fund VARCHAR(5)
,Date DATE
,Amount MONEY
);
INSERT INTO #FundAmounts
VALUES
(1, 'A', '01/20/2015', 250)
,(2, 'A', '02/28/2015', 300)
,(3, 'A', '03/20/2015', 400)
,(4, 'A', '03/30/2015', 200)
,(5, 'B', '04/01/2015', 500)
,(6, 'B', '04/01/2015', 600);
SELECT
F.Fund
,D.SelectedDate AS Date
,SUM(F.Amount) AS SumOfAmount
FROM
(
SELECT
SelectedDate
,LAG(SelectedDate,1,'1/1/1900') OVER (ORDER BY SelectedDate ASC) AS PreviousDate
FROM #Dates
) D
JOIN
#FundAmounts F
ON
F.Date BETWEEN DATEADD(DAY,1,D.PreviousDate) AND D.SelectedDate
GROUP BY
D.SelectedDate
,F.Fund
EDIT: Here is alternative to the LAG function for this example:
FROM
(
SELECT
SelectedDate
,ISNULL((SELECT TOP 1 SelectedDate FROM #Dates WHERE SelectedDate < Dates.SelectedDate ORDER BY SelectedDate DESC),'1/1/1900') AS PreviousDate
FROM #Dates Dates
) D
If i change your incorrect sample data to ...
CREATE TABLE TableName
([Id] int, [Fund] varchar(1), [Date] datetime, [Amount] int)
;
INSERT INTO TableName
([Id], [Fund], [Date], [Amount])
VALUES
(1, 'A', '2015-01-28 00:00:00', 250),
(2, 'A', '2015-01-28 00:00:00', 300),
(3, 'A', '2015-03-30 00:00:00', 400),
(4, 'A', '2015-03-30 00:00:00', 200),
(5, 'B', '2015-04-01 00:00:00', 500),
(6, 'B', '2015-04-01 00:00:00', 600)
;
this query using GROUP BY works:
SELECT MIN(Id) AS Id,
MIN(Fund) AS Fund,
[Date],
SUM(Amount) AS SumOfAmount
FROM dbo.TableName t
WHERE [Date] IN ('01/28/2015','03/30/2015','04/01/2015')
GROUP BY [Date]
Demo
Initially i have used Row_number and month function to pick max date of every month and in 2nd cte i did sum of amounts and joined them..may be this result set matches your out put
declare #t table (Id int,Fund Varchar(1),Dated date,amount int)
insert into #t (id,Fund,dated,amount) values (1,'A','01/20/2015',250),
(2,'A','01/28/2015',300),
(3,'A','03/20/2015',400),
(4,'A','03/30/2015',200),
(5,'B','04/01/2015',600),
(6,'B','04/01/2015',500)
;with cte as (
select ID,Fund,Amount,Dated,ROW_NUMBER() OVER
(PARTITION BY DATEDIFF(MONTH, '20000101', dated)ORDER BY dated desc)AS RN from #t
group by ID,Fund,DATED,Amount
),
CTE2 AS
(select SUM(amount)Amt from #t
GROUP BY MONTH(dated))
,CTE3 AS
(Select Amt,ROW_NUMBER()OVER (ORDER BY amt)R from cte2)
,CTE4 AS
(
Select DISTINCT C.ID As ID,
C.Fund As Fund,
C.Dated As Dated
,ROW_NUMBER()OVER (PARTITION BY RN ORDER BY (SELECT NULL))R
from cte C INNER JOIN CTE3 CC ON c.RN = CC.R
Where C.RN = 1
GROUP BY C.ID,C.Fund,C.RN,C.Dated )
select C.R,C.Fund,C.Dated,cc.Amt from CTE4 C INNER JOIN CTE3 CC
ON c.R = cc.R
declare #TableName table([Id] int, [Fund] varchar(1), [Date] datetime, [Amount] int)
declare #Sample table([SampleDate] datetime)
INSERT INTO #TableName
([Id], [Fund], [Date], [Amount])
VALUES
(1, 'A', '20150120 00:00:00', 250),
(2, 'A', '20150128 00:00:00', 300),
(3, 'A', '20150320 00:00:00', 400),
(4, 'A', '20150330 00:00:00', 200),
(5, 'B', '20150401 00:00:00', 500),
(6, 'B', '20150401 00:00:00', 600)
INSERT INTO #Sample ([SampleDate])
values ('20150128 00:00:00'), ('20150330 00:00:00'), ('20150401 00:00:00')
-- select * from #TableName
-- select * from #Sample
;WITH groups AS (
SELECT [Fund], [Date], [AMOUNT], MIN([SampleDate]) [SampleDate] FROM #TableName
JOIN #Sample ON [Date] <= [SampleDate]
GROUP BY [Fund], [Date], [AMOUNT])
SELECT [Fund], [SampleDate], SUM([AMOUNT]) FROM groups
GROUP BY [Fund], [SampleDate]
Explanation:
The CTE groups finds the earliest SampleDate which is later than (or equals to) your
data's date and enriches your data accordingly, thus giving them the group to be summed up in.
After that, you can group on the derived date.
Need help with SQL to show concurrency by person for every minute in a day.
for a data set below:
drop table test
create table test (person varchar(2), caseid varchar(3), starttime datetime, endtime datetime)
insert into test values ('aa', '1', '01/01/2013 06:42', '01/01/2013 07:06')
insert into test values ('aa', '1', '01/01/2013 07:31', '01/01/2013 09:38')
insert into test values ('aa', '2', '01/01/2013 08:37', '01/01/2013 11:44')
insert into test values ('aa', '3','01/01/2013 09:39', '01/01/2013 11:31')
insert into test values ('aa', '4','01/01/2013 11:09', '01/01/2013 13:30')
insert into test values ('aa', '5','01/01/2013 12:05', '01/01/2013 15:38')
insert into test values ('aa', '6', '01/01/2013 13:58', '01/01/2013 14:13')
insert into test values ('aa', '7', '01/01/2013 15:53', '01/01/2013 16:14')
insert into test values ('bb', '8', '01/01/2013 08:42', '01/01/2013 09:06')
insert into test values ('bb', '8', '01/01/2013 10:31', '01/01/2013 19:38')
insert into test values ('bb', '8','01/01/2013 20:37', '01/01/2013 21:44')
insert into test values ('bb', '9', '01/01/2013 09:39', '01/01/2013 11:31')
insert into test values ('bb', '9', '01/01/2013 11:45', '01/01/2013 13:30')
insert into test values ('bb', '9', '01/01/2013 12:05', '01/01/2013 15:38')
insert into test values ('bb', '10', '01/01/2013 13:58', '01/01/2013 14:13')
insert into test values ('bb', '10', '01/01/2013 15:53', '01/01/2013 16:14')
the result needs to be similar to the following:
aa 01/01/2013 6:42 1
aa 01/01/2013 6:43 1
aa 01/01/2013 6:44 1
....
....
aa 01/01/2013 8:37 2
aa 01/01/2013 8:38 2
....
....
bb 01/01/2013 8:42 1
bb 01/01/2013 8:43 1
bb 01/01/2013 10:31 2
....
....
Thanks
You can do this with a correlated subquery:
Select t.*,
(Select count(*)
From t t2
Where t2. Start <= t.start and
T2.end >= t.end
) numoverlaps
From t
(Apologies for syntax errors; I'm on a mobile device)
This finds concurrency at every time in the input data. It does not do it for every minute of time.
This seems to work, but there may be a more elegant solution:
-- get range of days involved
declare #minDate date = (select MIN(starttime) from test)
declare #maxDate date = (select MAX(endtime) from test)
-- create table containing all days
if OBJECT_ID('tempdb..#days') is not null
drop table #days
create table #days (d date)
declare #day date = #minDate
while #day <= #maxDate
begin
insert #days (d) values (#day)
set #day = DATEADD(day, 1, #day)
end
-- create table containing all minutes in the day
if OBJECT_ID('tempdb..#minutes') is not null
drop table #minutes
create table #minutes (m int)
declare #minute int = 0
while #minute < 24*60
begin
insert #minutes (m) values (#minute)
set #minute = #minute + 1
end
select person, dateadd(minute, m, convert(datetime, startdate)), c from
(
select person, m, startdate, count(m) c from
(
-- cross join to select all days and minutes
select d.d, m.m from #days d cross join #minutes m
)
t0
inner join
(
select
person,
convert(date, starttime) startdate,
datediff(minute, convert(date, starttime), starttime) startmin,
datediff(minute, convert(date, endtime), endtime) endmin
from test
)
t1
on t0.m between t1.startmin and t1.endmin
and t0.d = t1.startdate
group by person, m, startdate
)
t2
order by person, startdate, m, c
Here is how I would approach it if using a database that supports CTE and inline views:
First a CTE to generate a two-col listing of the (24*60) minutes of the day for a specified date:
time1 time2
2013-02-12 00:00, 2013-02-12 00:01
.
.
.
2013-02-12 23:59, 2013-02-13 00:00
Left join that CTE to your cases table where cases.starttime between time1 and time2 or cases.endtime between time1 and time2. That brings back either nulls where no part of the case was ongoing during that minute or the caseid and personid when a case was ongoing during that minute.
Make the above an inline view. You end up with a set of all minutes in the day and the left-joined caseid and personid, or nulls:
time1, time2, caseid, personid
If you select from that inline view where caseid is not null you end up with the minutes where one or more cases was ongoing; if you then group by personid, time1 and count(caseid) you get the tally of cases per person in that particular one-minute time slot.