Documentation

Comparing values from different buckets

This example uses NOAA water sample data.

This example compares the value from the latest point to an average value stored in another bucket. This is useful when using the average value to calculate a threshold check.

The following query:

  • Uses range() to define a time range.
  • Gets the last value in the means bucket and compares it to the last value in the noaa bucket using last().
  • Uses join() to combine the results
  • Uses map() to calculate the differences
means = from(bucket: "weekly_means")
    |> range(start: 2019-09-01T00:00:00Z)
    |> last()
    |> keep(columns: ["_value", "location"])

latest = from(bucket: "noaa")
    |> range(start: 2019-09-01T00:00:00Z)
    |> filter(fn: (r) => r._measurement == "average_temperature")
    |> last()
    |> keep(columns: ["_value", "location"])

join(tables: {mean: means, reading: latest}, on: ["location"])
    |> map(fn: (r) => ({r with deviation: r._value_reading - r._value_mean}))

Example results

location _value_mean _value_reading deviation
coyote_creek 79.82710622710623 89 9.172893772893772
santa_monica 80.20451339915374 85 4.79548660084626

Was this page helpful?

Thank you for your feedback!


Introducing InfluxDB Clustered

A highly available InfluxDB 3.0 cluster on your own infrastructure.

InfluxDB Clustered is a highly available InfluxDB 3.0 cluster built for high write and query workloads on your own infrastructure.

InfluxDB Clustered is currently in limited availability and is only available to a limited group of InfluxData customers. If interested in being part of the limited access group, please contact the InfluxData Sales team.

Learn more
Contact InfluxData Sales

The future of Flux

Flux is going into maintenance mode. You can continue using it as you currently are without any changes to your code.

Flux is going into maintenance mode and will not be supported in InfluxDB 3.0. This was a decision based on the broad demand for SQL and the continued growth and adoption of InfluxQL. We are continuing to support Flux for users in 1.x and 2.x so you can continue using it with no changes to your code. If you are interested in transitioning to InfluxDB 3.0 and want to future-proof your code, we suggest using InfluxQL.

For information about the future of Flux, see the following:

InfluxDB Cloud powered by TSM