FirstIn and LastOut is not working - sql-server

Question

I want to calculate total working hours of an employee for specific day. With my current query it is giving me records for all days but what I want is to get for each day.
Like I have 2 days records so it should show 2 rows but instead it is only returning one.
DECLARE #T TABLE
([EmpID] int, [TimeIn] datetime, [TimeOut] datetime);
INSERT INTO #T
([EmpID], [TimeIn], [TimeOut]) VALUES
(1, '2018-01-10 9:00:00', NULL),
(1, NULL, '2018-01-10 11:00'),
(1, '2018-01-10 11:30:00', NULL),
(1, NULL, '2018-01-10 13:00'),
(1, '2018-01-10 13:30:00', NULL),
(1, NULL, '2018-01-10 18:00'),
(1, '2018-01-11 9:00:00', NULL),
(1, NULL, '2018-01-11 11:00'),
(1, '2018-01-11 11:30:00', NULL),
(1, NULL, '2018-01-11 13:00'),
(1, '2018-01-11 13:30:00', NULL),
(1, NULL, '2018-01-11 18:00')
;
;WITH TM
AS
(
SELECT
EmpID,
MIN([TimeIn]) as StartTime,
MAX([TimeOut]) as EndTime
FROM #T
GROUP BY EmpId
)
SELECT
*,
HoursSpent = DATEDIFF(HOUR, StartTime, EndTime)
FROM TM
What I really want is that by default it should give me yesterday's report or otherwise I could pass value at run time too like I want report of 10th Jan 2018 and something like that but I guess that part is far away as I'm stuck here.

Answer 1

Try:
;WITH cte AS
(
SELECT empid
, MIN(timein) timein
, MAX(timeout) timeout
, cast(coalesce(timein, timeout) AS DATE) d
FROM #T
GROUP BY empid, cast(coalesce(timein, timeout) AS DATE)
)
SELECT empid
, d AS Day
, DateDiff(HOUR, TimeIn, TimeOut) [Hours Worked]
FROM cte
ORDER BY d ASC

Answer 2

;WITH
TM1 as
(
SELECT EmpID,
convert(date, COALESCE(TimeIn, [TimeOut])) as [Date],
TimeIn,
[TimeOut],
grp = (ROW_NUMBER() OVER (PARTITION BY EmpID ORDER BY COALESCE(TimeIn, [TimeOut])) - 1) / 2 + 1
from #T
),
TM2
AS
(
SELECT EmpID,
[Date],
DATEDIFF(HOUR, MIN([TimeIn]), MAX([TimeOut])) as HoursSpent
FROM TM1
GROUP BY EmpID, [Date], grp
)
SELECT EmpID, [Date], SUM(HoursSpent) as HoursSpent
FROM TM2
GROUP BY EmpID, [Date]
/*
RESULT :
EmpID Date HoursSpent
1 2018-01-10 9
1 2018-01-11 9
*/
if you want higher precision, use DATEDIFF(minute) and divide by 60.0

Answer 3

Just Add a Variable to Specify the Date
DECLARE #MyDate DATE
Assign the date to the Variable if you want to get the records for a specific date else keep it NULL.
Now, Change your Code of the Common Table Expression TM as below -- To Add the Where Condition
;WITH TM
AS
(
SELECT
EmpID,
MIN([TimeIn]) as StartTime,
MAX([TimeOut]) as EndTime
FROM #T
WHERE
CAST(ISNULL(#MyDate,GETDATE()-1) AS DATE) = CAST(ISNULL([TimeIn],[TimeOut]) AS DATE)
GROUP BY EmpId
)
SELECT
*,
HoursSpent = DATEDIFF(HOUR, StartTime, EndTime)
FROM TM
When #MyDate = '2018-01-10'
When #MyDate IS NULL