group() function

group() regroups input data by modifying group key of input tables.

Note: Group does not guarantee sort order. To ensure data is sorted correctly, use sort() after group().

Function type signature

(<-tables: stream[A], ?columns: [string], ?mode: string) => stream[A] where A: Record

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Parameters

columns

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

Note: When columns is set to an empty array, group() ungroups all data merges it into a single output table.

mode

Grouping mode. Default is by.

Available modes:

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

tables

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

Examples

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

Group by specific columns

import "sampledata"

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

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Input data

Output data

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Group by everything except time

import "sampledata"

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

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Input data

Output data

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Ungroup data

import "sampledata"

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

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Input data

Output data

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