union() function

The union() function concatenates two or more input streams into a single output stream. In tables that have identical schemas and group keys, contents of the tables will be concatenated in the output stream. The output schemas of the union() function is the union of all input schemas.

union() does not preserve the sort order of the rows within tables. A sort operation may be added if a specific sort order is needed.

Function type: Transformation Output data type: Object

union(tables: ["table1", "table2"])



Specifies the streams to union together. There must be at least two streams.

Data type: Array of streams


left = from(bucket: "test")
  |> range(start: 2018-05-22T19:53:00Z, stop: 2018-05-22T19:53:50Z)
  |> filter(fn: (r) =>
    r._field == "usage_guest" or
    r._field == "usage_guest_nice"
  |> drop(columns: ["_start", "_stop"])

right = from(bucket: "test")
  |> range(start: 2018-05-22T19:53:50Z, stop: 2018-05-22T19:54:20Z)
  |> filter(fn: (r) =>
    r._field == "usage_guest" or
    r._field == "usage_idle"
  |> drop(columns: ["_start", "_stop"])

union(tables: [left, right])

Bug Reports and Feedback

Thank you for being willing to help test InfluxDB v2.0 alpha! Feedback and bug reports are welcome and encouraged both for InfluxDB and this documentation.

Submit feedback in the InfluxData Community