docs-v2/content/flux/v0/stdlib/experimental/distinct.md

title	description	menu	weight	flux/v0/tags	introduced
experimental.distinct() function	`experimental.distinct()` returns unique values from the `_value` column.	flux_v0_ref name parent identifier experimental.distinct experimental experimental/distinct	101	transformations selectors	0.112.0

experimental.distinct() returns unique values from the _value column.

The _value of each output record is set to a distinct value in the specified column. null is considered a distinct value.

experimental.distinct() drops all columns not in the group key and drops empty tables.

Function type signature

(<-tables: stream[{A with _value: B}]) => stream[{A with _value: B}]

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Parameters

tables

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

Examples

Return distinct values from each input table

import "experimental"
import "sampledata"

sampledata.int(includeNull: true)
    |> experimental.distinct()

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Input data

_time	_value	*tag
2021-01-01T00:00:00Z	-2	t1
2021-01-01T00:00:10Z		t1
2021-01-01T00:00:20Z	7	t1
2021-01-01T00:00:30Z		t1
2021-01-01T00:00:40Z		t1
2021-01-01T00:00:50Z	4	t1

_time	_value	*tag
2021-01-01T00:00:00Z		t2
2021-01-01T00:00:10Z	4	t2
2021-01-01T00:00:20Z	-3	t2
2021-01-01T00:00:30Z	19	t2
2021-01-01T00:00:40Z		t2
2021-01-01T00:00:50Z	1	t2

Output data

*tag	_value
t1	-2
t1
t1	7
t1	4

*tag	_value
t2
t2	4
t2	-3
t2	19
t2	1

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