InfluxDb

https://www.sqlpac.com/en/documents/influxdb-flux-language-advanced-features.html#influxdb-v2-quick-reminders

from(bucket: "bucket")
  |> range(start: -2h)
  |> filter(fn: (r) =>  exists r.nas_name)
//   |> group(columns: ["nas_name","_measurment"])
  |>last()
  |> yield(name: "unique")

• https://www.influxdata.com/blog/tldr-influxdb-tech-tips-converting-influxql-queries-flux-queries/