.. _auto_keyvalue_union:

*UNION TWO KEYVALUES*
=====================

Merges two key-value collections into a single unified dataset by performing a union operation. Use this worker when you need to combine parameters or metadata from two separate key-value sources into one output.

When to use
-----------

Classification: **process**.

Tagged: ``combine``, ``keyvalue``, ``merge``, ``transform``, ``union``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Keyvalue Base
     - keyvalue_base
     - keyvalue
     - —
     - 
     - The primary key-value collection to use as the base of the union; keys from this input take precedence in the merged result. Optional — leave empty to treat the merge input as the sole source.
   * - Keyvalue To Merge
     - keyvalueto_merge
     - keyvalue
     - —
     - 
     - The secondary key-value collection whose entries are merged into the base; any keys not present in the base are added, and duplicate-key behaviour follows union semantics. Optional — repeatable up to once.

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - keyvalue_union_output_1
     - keyvalue_union_output_1
     - dataset
     - A dataset containing the unified key-value pairs from both inputs, with all unique keys from both collections represented in a single flat structure.

Disciplines
-----------

- data.dataset.transform

Runnable example
----------------

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=keyvalue_union <https://www.d3view.com/api/workflow/example?id=keyvalue_union>`_

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>keyvalue_union</code>. Schema hash: <code>0ea31ecb27d9</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>