How to calculate the night working shift in SQL server?

Question

I'm using Fingerprint system to record the IN OUT log of all employee in 4 shifts .Normal shift(08:00-> 17:00) , Shift 1:(06-> 14:00), Shift 2: (14:00-> 22:00) Shift 3:(22:00-> 06:00 tomorrow) . I have 2 main table :

When I use the left join :

select e.Id as EmpID,CAST(PunchTime as DATE)CheckDate,MIN(cast(a.PunchTime as Time))[TimeIN], max(cast(a.PunchTime as Time))[Time_OUT]
from Employee e
left join AttLog a
on a.EnrollNumber=e.EnrollNumber 
group by e.Id,CAST(PunchTime as DATE)

and when I use the inner join :

select e.Id as EmpID,CAST(PunchTime as DATE)CheckDate,MIN(cast(a.PunchTime as Time))[TimeIN], max(cast(a.PunchTime as Time))[Time_OUT]
from Employee e
inner join AttLog a
on a.EnrollNumber=e.EnrollNumber 
group by e.Id,CAST(PunchTime as DATE)

Then , you see when using left join we get all the employee including null time. And when we use inner join we just get the Time IN = Time OUT if the employee working in the Shift 3 (22:00 today to 06:00 tomorrow) . So my question is how to calculate the time IN and OUT of Shift 3. And if the employee punch only IN then Time OUT = Time IN , how can display time OUT as 00:00:00 in that case. I want to output like this:

EmpID  CheckDate   TimeIN                       Time_OUT
5      2015-08-19    2015-08-19 07:51:29.000      2015-08-20 07:43:57.000
14     2015-08-19    2015-08-19 06:52:26.000      2015-08-19 00:00:00.000

EmpID 5 with normal working: 08:00->17:00 but he must took night duty so he must stay at the company until 08:00 tomorrow. EmpID 14 work in normal shift but she forgot to punch OUT. At the present with above data , the output like this:

EmpID  CheckDate   TimeIN                       Time_OUT
    5      2015-08-19    2015-08-19 07:51:29.000      2015-08-19 07:51:29.000
    5      2015-08-20    2015-08-20 07:43:57.000      2015-08-20 07:43:57.000
    14     2015-08-19    2015-08-19 06:52:26.000       2015-08-19 06:52:26.000

Answer 1

Here's an approach that sequences the punch times, and then self-joins with a recursive CTE to stitch times together. It's hard with a system like this to control for missed punches etc., but I tried show you a way you could do it by adding in an HoursWorked threshold.

/* Create some sample Employee punch data to test*/
IF OBJECT_ID('tempdb..#AttLogTest') IS NOT NULL
    DROP TABLE #AttLogTest

CREATE TABLE #AttLogTest (EnrollNumber INT NOT NULL, PunchTime DATETIME NOT NULL)

INSERT INTO #AttLogTest (EnrollNumber, PunchTime)
SELECT 10, '2015-08-01 08:01:03' UNION ALL
SELECT 10, '2015-08-02 07:57:35' UNION ALL
SELECT 10, '2015-08-01 16:15:23' UNION ALL
SELECT 10, '2015-08-02 16:17:46' UNION ALL
SELECT 12, '2015-08-01 21:59:31' UNION ALL
SELECT 12, '2015-08-02 05:59:02' UNION ALL
SELECT 12, '2015-08-02 22:02:28' UNION ALL
SELECT 12, '2015-08-03 06:01:24' UNION ALL
SELECT 14, '2015-08-01 07:59:01' UNION ALL
SELECT 14, '2015-08-02 07:58:16' UNION ALL
SELECT 14, '2015-08-02 16:02:48'

/* Employee time query logic below */

/* First, create a temp table that sequences the punch times for each employee */
IF OBJECT_ID('tempdb..#EmployeeTimeSequence') IS NOT NULL
    DROP TABLE #EmployeeTimeSequence

SELECT
    EnrollNumber
    ,PunchTime
    ,PunchSequence = ROW_NUMBER() OVER(PARTITION BY EnrollNumber ORDER BY PunchTime)
INTO #EmployeeTimeSequence
FROM #AttLogTest --Replace this with your dbo.AttLog table if this solution works for you
/*WHERE clause could be added here to filter for specific dates or EnrollNumbers */


/* If time between punches is greater than this threashold, then it will be treated as a missed punch
  in logic below. Remove this or modify as needed. */
DECLARE @MissedPunchThreshold int
SET @MissedPunchThreshold = 20

/* Next, create a recursive CTE which will stitch together the punch times and ensure punch times don't overlap when 
 self-joining to #EmployeeTimeSequence. */
;WITH EmployeeTimeCTE (EnrollNumber, CheckDate, Time_In, Time_Out, HoursBetweenPunch, PunchOutSequence)
AS (
    /* Anchor member */
    SELECT 
        ETS_In.EnrollNumber
        ,CAST(ETS_In.PunchTime AS DATE) AS CheckDate
        ,ETS_In.PunchTime AS Time_In
        ,ETS_Out.PunchTime AS Time_Out
        ,DateDiff(hour, ETS_In.PunchTime, ETS_Out.PunchTime) AS HoursBetweenPunch
        ,ETS_Out.PunchSequence AS PunchOutSequence
    FROM #EmployeeTimeSequence AS ETS_In
    LEFT OUTER JOIN #EmployeeTimeSequence AS ETS_Out
        ON ETS_In.EnrollNumber = ETS_Out.EnrollNumber
        AND ETS_Out.PunchSequence = ETS_In.PunchSequence + 1
    WHERE ETS_In.PunchSequence = 1

    UNION ALL
    /* Recursive memebr - build on top of anchor */
        SELECT 
            ETS_In.EnrollNumber
            ,CAST(ETS_In.PunchTime AS DATE) AS CheckDate
            ,ETS_In.PunchTime AS Time_In
            ,ETS_Out.PunchTime AS Time_Out
            ,DateDiff(hour, ETS_In.PunchTime, ETS_Out.PunchTime) AS HoursBetweenPunch
            ,ETS_Out.PunchSequence AS PunchOutSequence
    FROM #EmployeeTimeSequence AS ETS_In --get the time for the in punch
    INNER JOIN EmployeeTimeCTE ET
        ON ET.EnrollNumber = ETS_In.EnrollNumber
            AND ETS_In.PunchSequence =
                CASE
                    WHEN ET.HoursBetweenPunch > @MissedPunchThreshold -- if more than threshold, then treat as missed punch
                        THEN ET.PunchOutSequence -- then treat the previous out punch as the next in punch instead
                    ELSE ET.PunchOutSequence + 1  -- else join as usual to get the next punch in sequence
                END 
    INNER JOIN #EmployeeTimeSequence AS ETS_Out -- get the time for the out punch
        ON ETS_In.EnrollNumber = ETS_Out.EnrollNumber
        AND ETS_Out.PunchSequence = ETS_In.PunchSequence + 1
)
/* Now query the CTE */
SELECT 
    EnrollNumber AS EmpID
    ,CheckDate 
    ,Time_In
    ,CASE WHEN HoursBetweenPunch > @MissedPunchThreshold THEN NULL ELSE Time_Out END AS Time_Out
    ,CASE WHEN HoursBetweenPunch > @MissedPunchThreshold THEN NULL ELSE HoursBetweenPunch END AS HoursBetweenPunch
FROM EmployeeTimeCTE
ORDER BY EnrollNumber, CheckDate
OPTION (MAXRECURSION 1000)