Question

Okay, so I have a question about using columns in a case statement that might be null.

Again I have two tables the first looks like this UserActivity:

   userID    Action    Time
     1         25       12:00
     1         10       12:01
     1         12       12:35
     1          6       13:54
     2         10        6:47
     2         42        6:48
     3          8       11:54
     etc.

But the second now looks like this UserSchedule:

   userID      startTime1        stopTime1     startTime2    stoptime2  startTime3    stopTime3
     1            07:00            09:00         11:00         12:00       14:30         16:30
     2            11:00            12:30         14:00         15:30       
     3            14:00            15:00
    etc.

So I need to be able to evaluate when in relation to all of those start and stop times an Action took place. Some users will have up to 5 start/stop times in a day. Some will only have one.

This code was given to me to resolve an earlier issue by @Adam Wengler, and it works great if there is only one start and stop time. I’m unsure how to include the logic to test against each of the 5 potential start/stop columns and ignore them if they are empty.

  UPDATE ua
  SET ua.TimeStatusId = CASE
                    WHEN ua.Time >= us.Schedule_Start
                       AND ua.Time <= us.Schedule_stop THEN 1
                    WHEN ua.Time >= DATEADD(HOUR, -1, us.Schedule_Start)
                       AND ua.Time <= us.ScheduleStart THEN 0
                    WHEN ua.Time >= us.Schedule_Stop
                       AND ua.Time =< DATEADD(HOUR, 1, us.Schedule_Stop)
                       THEN 2
                    ELSE 3
                  END
  FROM dbo.UserActivity AS ua
  INNER JOIN dbo.userSchedule AS us ON ua.UserId = us.UserId

Answer 1

You can use the IsNull() function to resolve your issue