Time difference from now

I use Grafana table plugin to load a list of alarms stored on InfluxDB onto my Grafana dashboard as shown above. I want to add another column to this table to show how much time has passed since each alarm. I tried the followings on InfluxDB:

  • Execute a select statement like “select now() - time from alarms”
    • AFAIK, there’s no function now() in the select clause
  • Getting the latest time from _internal.runtime and use the last time instead of now()
    • cannot use select statement from two measurements

Is it possible only using InfluxQL? Otherwise, should I modify Grafana table plugin to achieve the goal?