keyValues() function

keyValues() returns a stream of tables with each input tables’ group key and two columns, _key and _value, that correspond to unique column label and value pairs for each input table.

Function type signature

(<-tables: stream[A], ?keyColumns: [string]) => stream[{B with _value: C, _key: string}] where A: Record, B: Record

Parameters

keyColumns

List of columns from which values are extracted.

All columns must be of the same type. Each input table must have all of the columns in the keyColumns parameter.

tables

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

Examples

Get key values from explicitly defined columns

data
    |> keyValues(keyColumns: ["sensorID", "_field"])