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getColumn() function

content/flux/v0/stdlib/universe/getcolumn.md

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<!------------------------------------------------------------------------------ IMPORTANT: This page was generated from comments in the Flux source code. Any edits made directly to this page will be overwritten the next time the documentation is generated. To make updates to this documentation, update the function comments above the function definition in the Flux source code: https://github.com/influxdata/flux/blob/master/stdlib/universe/universe.flux#L2996-L2996 Contributing to Flux: https://github.com/influxdata/flux#contributing Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md ------------------------------------------------------------------------------->

getColumn() extracts a specified column from a table as an array.

If the specified column is not present in the table, the function returns an error.

Function type signature
js
(<-table: stream[A], column: string) => [B] where A: Record

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

Parameters

column

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

table

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

Examples

Extract an array of column values from a table

js
import "sampledata"

sampledata.int()
    |> tableFind(fn: (key) => key.tag == "t1")
    |> getColumn(column: "_value")// Returns [-2, 10, 7, 17, 15, 4]

Extract an array of column values and display them in a table

js
import "array"
import "sampledata"

columnData =
    sampledata.int()
        |> tableFind(fn: (key) => key.tag == "t1")
        |> getColumn(column: "_value")

array.from(rows: [{_value: display(v: columnData)}])