SQL Select Statement for Time and attendance for a month - sql

Question

Anyone can help with this one please? Our attendance system generates the following data:
Empid Department Timestamp Read_ID
3221 IT 2017-01-29 11:12:00.000 1
5565 IT 2017-01-29 12:28:06.000 1
5565 IT 2017-01-29 12:28:07.000 1
3221 IT 2017-01-29 13:12:00.000 2
5565 IT 2017-01-29 13:28:06.000 2
3221 IT 2017-01-30 07:42:15.000 1
3221 IT 2017-01-30 16:16:15.000 2
3221 IT 2017-01-31 09:05:00.000 1
3221 IT 2017-01-31 11:05:00.000 2
3221 IT 2017-01-31 13:20:00.000 1
3221 IT 2017-01-31 16:10:00.000 2
Where Read_ID value are :
1 = Entry
2 = Exit
I'm looking for SQL query to run on MS SQL 2014 that summarize attendance time for each employee on monthly basis, for instance
Empid Department Year Month TotalHours
3221 IT 2017 1 15:24
5565 IT 2017 1 01:00

Answer 1

This query should give you the result you need. It works by selecting each entries, and joining it with the next exit of the same employee (entries without further exits are ignored) : this gives us the duration of this employee shift. Then results are aggregated and shift durations are sumed in each group.
SELECT
t1.empid,
t1.department,
YEAR(t1.timestamp) Year,
MONTH(t1.timestamp) Month,
CONVERT(
varchar(12),
DATEADD(minute, SUM(DATEDIFF(minute, t1.timestamp, t2.timestamp)), 0),
114
) TotalHours
FROM
mytable t1
INNER JOIN mytable t2
ON t1.empid = t2.empid
AND t2.read_id = 2
AND t2.timestamp = (
SELECT MIN(timestamp)
FROM mytable
WHERE
read_id = 2
AND empid = t2.empid
AND timestamp > t1.timestamp
)
WHERE
t1.read_id = 1
GROUP BY t1.empid, t1.department, YEAR(t1.timestamp), MONTH(t1.timestamp)
ORDER BY 1, 2, 3, 4
Returns :
empid | department | Year | Month | TotalHours
----: | :--------- | ---: | ----: | :-----------
3221 | IT | 2017 | 1 | 15:24:00:000
5565 | IT | 2017 | 1 | 02:00:00:000
DB Fiddle demo on SQL Server 2014
There is an edge case, however, where an employee enters twice and then exists (this happens in your data, where employee 5565 enters at 29/01/2017 12:28:06 and at 29/01/2017 12:28:07, and then exits at 29/01/2017 13:28:06. The above query will take in account the two overlaping entries and map them to the same exit, resulting in this hour of work being counted twice.
While this matches your expected results, is this what you really want ? Here is an alternative query that , if several consecutive of the same employee entries happen, only takes in account the latest one :
SELECT
t1.empid,
t1.department,
YEAR(t1.timestamp) Year,
MONTH(t1.timestamp) Month,
CONVERT(
varchar(12),
DATEADD(minute, SUM(DATEDIFF(minute, t1.timestamp, t2.timestamp)), 0),
114
) TotalHours
FROM
mytable t1
INNER JOIN mytable t2
ON t1.empid = t2.empid
AND t2.read_id = 2
AND t2.timestamp = (
SELECT MIN(timestamp)
FROM mytable
WHERE
read_id = 2
AND empid = t2.empid
AND timestamp > t1.timestamp
)
WHERE
t1.read_id = 1
AND NOT EXISTS (
SELECT 1
FROM mytable
WHERE
read_id = 1
AND empid = t1.empid
AND timestamp > t1.timestamp
AND timestamp < t2.timestamp
)
GROUP BY t1.empid, t1.department, YEAR(t1.timestamp), MONTH(t1.timestamp)
ORDER BY 1, 2, 3, 4
Returns :
empid | department | Year | Month | TotalHours
----: | :--------- | ---: | ----: | :-----------
3221 | IT | 2017 | 1 | 15:24:00:000
5565 | IT | 2017 | 1 | 01:00:00:000
DB fiddle

Answer 2

Try this. I was not sure what time format would satisfy your system, so I put both:
SELECT * INTO #Tbl3 FROM (VALUES
(3221,'IT','2017-01-29 11:12:00.000',1),
(5565,'IT','2017-01-29 12:28:06.000',1),
(5565,'IT','2017-01-29 12:28:07.000',1),
(3221,'IT','2017-01-29 13:12:00.000',2),
(5565,'IT','2017-01-29 13:28:06.000',2),
(3221,'IT','2017-01-30 07:42:15.000',1),
(3221,'IT','2017-01-30 16:16:15.000',2),
(3221,'IT','2017-01-31 09:05:00.000',1),
(3221,'IT','2017-01-31 11:05:00.000',2),
(3221,'IT','2017-01-31 13:20:00.000',1),
(3221,'IT','2017-01-31 16:10:00.000',2))
x (Empid,Department,Timestamp,Read_ID)
;With cte as (
SELECT t1.Empid, t1.Department
, [Year] = Year(t1.Timestamp)
, [Month] = Month(t1.Timestamp)
, Seconds = SUM(DATEDIFF(second, t1.Timestamp, t2.Timestamp))
FROM #Tbl3 as t1
OUTER APPLY (
SELECT Timestamp = MIN(t.Timestamp)
FROM #Tbl3 as t
WHERE t.Department = t1.Department and t.Empid = t1.Empid
and t.Timestamp > t1.Timestamp and t.Read_ID = 2
) as t2
WHERE t1.Read_ID = 1
GROUP BY t1.Empid, t1.Department, Year(t1.Timestamp), Month(t1.Timestamp))
SELECT *, TotalHours = Seconds / 3600., TotalTime =
RIGHT('0'+CAST(Seconds / 3600 as VARCHAR),2) + ':' +
RIGHT('0'+CAST((Seconds % 3600) / 60 as VARCHAR),2) + ':' +
RIGHT('0'+CAST(Seconds % 60 as VARCHAR),2)
FROM cte;