======= Tableau

The Presto web connector for Tableau lets users run queries from Tableau against Presto. It implements the functions in the Tableau web connector API <https://www.tableau.com/developer/tools/web-data-connector>_.

When creating a new web data source, Tableau will ask for the URL of the web connector. Use the following URL, replacing example.net:8080 with the hostname and port number of the Presto coordinator (the default port is 8080):

.. code-block:: none

 http://example.net:8080/tableau/presto-connector.html

When Tableau first loads the Presto web connector, it will render an HTML form. In this form you need to fill in details such as your user name, the catalog and the schema you want to query, the data source name, session parameters you want to set and finally the SQL query to run. After you click Submit, the query will be submitted to the Presto coordinator and Tableau will then create an extract out of the results retrieved from the coordinator, page by page. After Tableau is done extracting the results of your query, you can then use this extract for further analysis with Tableau.

.. note:: With the Presto web connector, you can only create Tableau extracts, because the web connector API currently does not support the live mode.

 The web connector API only supports a subset of the data types available
 in Presto. In particular, the Tableau web connector API currently supports
 the following Tableau data types:
 ``bool``, ``date``, ``datetime``, ``float``, ``int`` and ``string``.
 Presto ``boolean`` and ``date`` types will be converted to the Tableau
 data types ``bool`` and ``date``, respectively, on the Tableau client side.
 Any other Presto types such as ``array``, ``map``, ``row``, ``double``,
 ``bigint``, etc., will be converted to a Tableau ``string`` as they do
 not map to any Tableau type.