filter() function

Warning! This page documents an earlier version of Flux, which is no longer actively developed. Flux v0.12 is the most recent stable version of Flux.

The filter() function filters data based on conditions defined in a predicate function (fn). The output tables have the same schema as the corresponding input tables.

Function type: Transformation
Output data type: Object

filter(fn: (r) => r._measurement == "cpu")

Parameters

fn

A single argument function that evaluates true or false. Records are passed to the function. Those that evaluate to true are included in the output tables.

Data type: Function

Objects evaluated in fn functions are represented by r, short for “record” or “row”.

Examples

from(bucket:"telegraf/autogen")
  |> range(start:-1h)
  |> filter(fn: (r) =>
    r._measurement == "cpu" AND
    r._field == "usage_system" AND
    r.cpu == "cpu-total"
  )

SELECT