.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "_auto_examples/aequilibrae_project/plot_connections.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download__auto_examples_aequilibrae_project_plot_connections.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr__auto_examples_aequilibrae_project_plot_connections.py:


.. _example_aequilibrae_connections:

Project Connections
===================

In this example, we show how to use AequilibraE's database connections within a project.

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.. admonition:: References

  * :doc:`../../aequilibrae_project`

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.. seealso::
    Several functions, methods, classes and modules are used in this example:

    * :func:`aequilibrae.project.project.Project.db_connection`
    * :func:`aequilibrae.project.project.Project.db_connection_spatial`
    * :func:`aequilibrae.project.project.Project.results_connection`
    * :func:`aequilibrae.project.project.Project.transit_connection`

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.. code-block:: Python


    # Imports
    from uuid import uuid4
    from tempfile import gettempdir
    from pathlib import Path

    import geopandas as gpd
    import pandas as pd

    from aequilibrae.utils.create_example import create_example


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.. code-block:: Python


    # We create the example project inside our temp folder.
    fldr = Path(gettempdir()) / uuid4().hex
    project = create_example(fldr, "sioux_falls")


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All AequilibraE projects presents four types of connections in the form of properties:

   * General connection to the project database
   * Spatial connection to the project database
   * General connection to the results database
   * Spatial connection to the transit database

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Each connection can be easily accessed as follows:

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.. code-block:: Python

    with project.db_connection as conn:
        matrices = pd.read_sql("SELECT * FROM matrices", conn)


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.. code-block:: Python

    matrices


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We encourage using spatial connections only when handling spatial data.

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.. code-block:: Python

    with project.db_connection_spatial as conn:
        nodes = gpd.read_postgis("SELECT zone_id, ST_AsBinary(geometry) geom FROM zones;", con=conn, geom_col="geom", crs=4326)


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.. code-block:: Python

    nodes.head()


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For accessing both results and transit databases, the procedure is the same.

When you're done, don't forget to close the project.

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.. code-block:: Python

    project.close()


.. _sphx_glr_download__auto_examples_aequilibrae_project_plot_connections.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_connections.ipynb <plot_connections.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_connections.py <plot_connections.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_connections.zip <plot_connections.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

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