docs-v2/content/flux/v0/stdlib/universe/duplicate.md

title	description	menu	weight	flux/v0/tags	introduced
duplicate() function	`duplicate()` duplicates a specified column in a table.	flux_v0_ref name parent identifier duplicate universe universe/duplicate	101	transformations	0.7.0

duplicate() duplicates a specified column in a table.

If the specified column is part of the group key, it will be duplicated, but the duplicate column will not be part of the output’s group key.

Function type signature

(<-tables: stream[A], as: string, column: string) => stream[B] where A: Record, B: Record

{{% caption %}} For more information, see Function type signatures. {{% /caption %}}

Parameters

column

({{< req >}}) Column to duplicate.

as

({{< req >}}) Name to assign to the duplicate column.

If the as column already exists, it will be overwritten by the duplicated column.

tables

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

Examples

Duplicate a column

import "sampledata"

sampledata.int()
    |> duplicate(column: "tag", as: "tag_dup")

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

Input data

_time	_value	*tag
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	t1

_time	_value	*tag
2021-01-01T00:00:00Z	19	t2
2021-01-01T00:00:10Z	4	t2
2021-01-01T00:00:20Z	-3	t2
2021-01-01T00:00:30Z	19	t2
2021-01-01T00:00:40Z	13	t2
2021-01-01T00:00:50Z	1	t2

Output data

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

_time	_value	*tag	tag_dup
2021-01-01T00:00:00Z	19	t2	t2
2021-01-01T00:00:10Z	4	t2	t2
2021-01-01T00:00:20Z	-3	t2	t2
2021-01-01T00:00:30Z	19	t2	t2
2021-01-01T00:00:40Z	13	t2	t2
2021-01-01T00:00:50Z	1	t2	t2

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