Sprinkler System

Hi I not getting the way how grafana work. So I like to ask you guys to help get me started

So I using OpenHab to run my Sprinkler System when turn on it send data to influxdb as 1 with an time and 0 when it turn off with a time.

so what i like to do is use grafana to tell me how much water was give IN the time.
I have started an graph but shows just 1 every time it turn on and drops when it turn off

what I think with the youtube video’s I have watch that is something to do in Metrics “SELECT” OR “GROUP_BY”