docs-v2/content/flux/v0.x/stdlib/universe/unique.md

title	description	aliases	menu	weight	flux/v0.x/tags	introduced
unique() function	The `unique()` function returns all records containing unique values in a specified column.	/influxdb/v2.0/reference/flux/functions/transformations/selectors/unique /influxdb/v2.0/reference/flux/functions/built-in/transformations/selectors/unique/ /influxdb/v2.0/reference/flux/stdlib/built-in/transformations/selectors/unique/ /influxdb/cloud/reference/flux/stdlib/built-in/transformations/selectors/unique/	flux_0_x_ref name parent unique universe	102	selectors transformations	0.7.0

The unique() function returns all records containing unique values in a specified column. Group keys, record columns, and values are not modified. unique() is a selector function.

unique(column: "_value")

{{% warn %}}

Empty tables

unique() drops empty tables. {{% /warn %}}

Parameters

column

Column to search for unique values. Defaults to "_value".

tables

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

Examples

{{% flux/sample-example-intro %}}

import "sampledata"

sampledata.int()
    |> unique()

{{< expand-wrapper >}} {{% expand "View input and output" %}} {{< flex >}} {{% flex-content %}}

Input data

{{% flux/sample "int" %}}

{{% /flex-content %}} {{% flex-content %}}

Output data

tag	_time	_value
t1	2021-01-01T00:00:00Z	-2
t1	2021-01-01T00:00:10Z	10
t1	2021-01-01T00:00:20Z	7
t1	2021-01-01T00:00:30Z	17
t1	2021-01-01T00:00:40Z	15
t1	2021-01-01T00:00:50Z	4

tag	_time	_value
t2	2021-01-01T00:00:00Z	19
t2	2021-01-01T00:00:10Z	4
t2	2021-01-01T00:00:20Z	-3
t2	2021-01-01T00:00:40Z	13
t2	2021-01-01T00:00:50Z	1

{{% /flex-content %}} {{< /flex >}} {{% /expand %}} {{< /expand-wrapper >}}