.. _auto_dataset_concat_columns:

*CONCATENATE COLUMNS INTO A NEW COLUMN*
=======================================

Combines values from two or more dataset columns into a single new string column, inserting an optional delimiter between each value. Use this worker to build composite keys, labels, or identifiers from existing fields in a dataset.

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

Classification: **process**.

Tagged: ``columns``, ``concat``, ``concatenate``, ``dataset_transform``, ``delimiter``, ``merge_columns``, ``new_column``, ``string``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Dataset
     - dataset
     - dataset
     - —
     - 
     - Input dataset whose columns will be concatenated; must contain at least the columns listed in the Columns parameter.
   * - Columns to concatenate
     - columns
     - scalar
     - —
     - 
     - Ordered list of column names whose row values will be joined together (multi-select, driven by the connected dataset).
   * - New Column Name
     - new_column_name
     - text
     - —
     - 
     - Name to assign to the newly created concatenated column; must be a non-empty string unique within the dataset.
   * - Delimiter
     - delimiter
     - text
     - —
     - 
     - String inserted between each concatenated value (e.g. ' ', ',', '-'); leave empty (default '') for no separator.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - dataset_concat_columns_output_1
     - dataset_concat_columns_output_1
     - dataset
     - Copy of the input dataset with one additional column appended, containing the concatenated values from the selected columns.

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=dataset_concat_columns <https://www.d3view.com/api/workflow/example?id=dataset_concat_columns>`_

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>dataset_concat_columns</code>. Schema hash: <code>f03eaef02324</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>