But as more devices enter the database this gets tedious. I am looking for a method query all devices and automatically subtract the most recent value from all values. I tried the following with no success:
Thank you so much for your help, Jay! I have adapted your example to my scenario and it does indeed subtract the last value of one measurement from all values. However I was hoping zero out each measurement separately, so that the very small differences between the values becomes visible. Do you think that’s possible?
Thank you so much! This is exactly the minimalist solution I was looking for. You are right, it’s super slow, so for practical purposes I’ll probably stick with something else. But very educating solution for sure.