Find value based on same row values

Question

I have a database with a table ( tblPersonnel ) that is populated with following data.

Name_Personnel      VesselName  SailoutDate Time_transfer   Direction
JB                  Flight 2    3/03/2016   10:38:00        UP
MH                  Flight 2    3/03/2016   10:38:00        UP
RS                  Flight 2    3/03/2016   10:38:00        UP
JB                  Flight 2    3/03/2016   11:40:00        DOWN
MH                  Flight 2    3/03/2016   11:40:00        DOWN
RS                  Flight 2    3/03/2016   11:40:00        DOWN

I need to query the total time for all personnel between the "UP" and "DOWN" time. I'd like to come with a output like this.

Name_Personnel      VesselName  SailoutDate Time_transfer_UP Time_transfer_DOWN  Total_time
JB                  Flight 2    3/03/2016   10:38:00         11:40:00            01:02
MH                  Flight 2    3/03/2016   10:14:00         11:49:00            01:35
RS                  Flight 2    3/03/2016   10:36:00         11:53:00            01:17

The Name_personnel , vesselname and sailoutdate always have an "UP" and a "Down" value. So these can be used to search matching rows.

How can I do this?

Answer 1

You can use conditional aggregation. The challenge is the total time. If you can live with total minutes, then it is pretty easy:

select Name_Personnel, VesselName, SailoutDate,
       max(iif(direction = 'UP', time_transfer, NULL)) as time_transfer_up,
       max(iif(direction = 'DOWN', time_transfer, NULL)) as time_transfer_down,
       datediff("minute",
                 max(iif(direction = 'UP', time_transfer, NULL)) 
                 max(iif(direction = 'DOWN', time_transfer, NULL))
               ) as minutes_diff
from tblPersonnel
group by Name_Personnel, VesselName, SailoutDate;

Answer 2

Thanks, Both answers worked fine, although I saw different output, as not all data was completely correctly filled.

My final query became this.

SELECT DateDiff("n",Max(IIf([direction]='UP',[time_transfer],Null)),Max(IIf([direction]='DOWN',[time_transfer],Null))) AS minutes_diff, tblPersons.Name_Personnel, tblPersons.VesselName, tblPersons.SailoutDate, tblPersons.Type, tblPersons.VesselName, Max(IIf([direction]='up',[time_transfer],Null)) AS Time_transfer_UP, Max(IIf([direction]='Down',[time_transfer],Null)) AS Time_tranfer_DOWN
FROM tblPersons, QRY_Numberofsailingdays
GROUP BY tblPersons.Name_Personnel, tblPersons.SailoutDate, tblPersons.Type, tblPersons.VesselName, tblPersons.VesselName
HAVING (((tblPersons.SailoutDate) Between [Forms]![FRM_Working_Time_Personnel]![TXT_startdate] And [Forms]![FRM_Working_Time_Personnel]![TXT_enddate]));