I have an event that is triggered when a device starts a process with a unique process id. When the process stops it sends another event with its Timestamp and the same process id. Now I want to calculate the total process time. So subtract the Timestamp from the Startevent from the Timestamp from the Endevent.
I tried multiple ways to accomplish this but they all failed.
Is it possible to save an item from a query to a variable? e.g. select @var = d.ProcessID from table d
or is it possible to make subqueries?? e.g. select d.TimeStamp from table d where d.ProcessID = (select e.ProcessID from table e)
Or if anyone has a different suggestion it would be great to have some input :)
Thanks in advance Greets