group() function

The group() function groups records based on their values for specific columns. It produces tables with new group keys based on provided properties. Specify an empty array of columns to ungroup data or merge all input tables into a single output table.

group(columns: ["host", "_measurement"], mode:"by")

// OR

group(columns: ["_time"], mode:"except")

// OR

group()

For more information about Flux table grouping, see Data model - Restructure tables.

data
  |> group()
  |> sort(columns: ["_time"])

Parameters

columns

List of columns to use in the grouping operation. Defaults to [].

mode

The mode used to group columns. Default is "by". The following modes are available:

• by: Groups records by columns defined in the columns parameter.
• except: Groups records by all columns except those defined in the columns parameter.

tables

Input data. Default is piped-forward data (<-).

Examples

The following examples use data provided by the sampledata package to show how group() transforms data.

• Group by specific columns
• Group by everything except time
• Ungroup data

Group by specific columns

import "sampledata"

sampledata.int()
  |> group(columns: ["_time", "tag"])

Group by everything except time

import "sampledata"

sampledata.int()
  |> group(columns: ["_time"], mode: "except")

Ungroup data

import "sampledata"

// Merge all tables into a single table
sampledata.int()
  |> group()