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https://github.com/sqlalchemy/sqlalchemy.git
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Mike Bayer
35 lines
1.1 KiB
Python
35 lines
1.1 KiB
Python
"""A naive example illustrating techniques to help
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embed PostGIS functionality.
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This example was originally developed in the hopes that it would be extrapolated into a comprehensive PostGIS integration layer. We are pleased to announce that this has come to fruition as `GeoAlchemy <http://www.geoalchemy.org/>`_.
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The example illustrates:
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* a DDL extension which allows CREATE/DROP to work in
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conjunction with AddGeometryColumn/DropGeometryColumn
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* a Geometry type, as well as a few subtypes, which
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convert result row values to a GIS-aware object,
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and also integrates with the DDL extension.
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* a GIS-aware object which stores a raw geometry value
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and provides a factory for functions such as AsText().
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* an ORM comparator which can override standard column
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methods on mapped objects to produce GIS operators.
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* an attribute event listener that intercepts strings
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and converts to GeomFromText().
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* a standalone operator example.
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The implementation is limited to only public, well known
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and simple to use extension points.
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E.g.::
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print session.query(Road).filter(Road.road_geom.intersects(r1.road_geom)).all()
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"""
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