74d9d71484
tests. Although the two are aliases of one another, it makes sense to be consistent and to use the one that the DB API prefers as well.
189 lines
9.8 KiB
Python
189 lines
9.8 KiB
Python
#------------------------------------------------------------------------------
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# Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
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#------------------------------------------------------------------------------
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#------------------------------------------------------------------------------
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# SpatialToGeoPandas.py
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# GeoPandas is a popular python library for working with geospatial data.
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# GeoPandas extends the Pandas data analysis library with geospatial support
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# using the Shapely library for geometry object support.
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#
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# See http://geopandas.org, https://pandas.pydata.org,
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# and https://github.com/Toblerity/Shapely.
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#
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# This example shows how to bring geometries from Oracle Spatial (SDO_GEOMETRY
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# data type) into GeoPandas and perform a simple spatial operation. While the
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# spatial operation we perform in Python could have been performed in the
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# Oracle database, this example targets use cases where Python with GeoPandas
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# is being used to combine and work with geospatial data from numerous
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# additional sources such as files and web services.
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#
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# This script requires cx_Oracle (5.3 and higher) as well as GeoPandas and its
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# dependencies (see http://geopandas.org/install.html).
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#------------------------------------------------------------------------------
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from __future__ import print_function
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import SampleEnv
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import cx_Oracle
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from shapely.wkb import loads
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import geopandas as gpd
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# create Oracle connection and cursor objects
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connection = cx_Oracle.connect(SampleEnv.MAIN_CONNECT_STRING)
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cursor = connection.cursor()
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# enable autocommit to avoid the additional round trip to the database to
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# perform a commit; this should not be used if multiple statements must be
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# executed for a single transaction
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connection.autocommit = True
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# define output type handler to fetch LOBs, avoiding the second round trip to
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# the database to read the LOB contents
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def OutputTypeHandler(cursor, name, defaultType, size, precision, scale):
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if defaultType == cx_Oracle.BLOB:
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return cursor.var(cx_Oracle.LONG_BINARY, arraysize = cursor.arraysize)
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connection.outputtypehandler = OutputTypeHandler
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# drop and create table
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print("Dropping and creating table...")
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cursor.execute("""
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begin
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execute immediate 'drop table TestStates';
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exception when others then
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if sqlcode <> -942 then
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raise;
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end if;
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end;""")
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cursor.execute("""
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create table TestStates (
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state VARCHAR2(30) not null,
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geometry SDO_GEOMETRY not null
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)""")
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# acquire types used for creating SDO_GEOMETRY objects
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typeObj = connection.gettype("MDSYS.SDO_GEOMETRY")
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elementInfoTypeObj = connection.gettype("MDSYS.SDO_ELEM_INFO_ARRAY")
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ordinateTypeObj = connection.gettype("MDSYS.SDO_ORDINATE_ARRAY")
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# define function for creating an SDO_GEOMETRY object
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def CreateGeometryObj(*ordinates):
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geometry = typeObj.newobject()
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geometry.SDO_GTYPE = 2003
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geometry.SDO_SRID = 8307
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geometry.SDO_ELEM_INFO = elementInfoTypeObj.newobject()
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geometry.SDO_ELEM_INFO.extend([1, 1003, 1])
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geometry.SDO_ORDINATES = ordinateTypeObj.newobject()
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geometry.SDO_ORDINATES.extend(ordinates)
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return geometry
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# create SDO_GEOMETRY objects for three adjacent states in the USA
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geometryNevada = CreateGeometryObj(-114.052025, 37.103989, -114.049797,
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37.000423, -113.484375, 37, -112.898598, 37.000401,-112.539604,
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37.000683, -112, 37.000977, -111.412048, 37.001514, -111.133018,
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37.00079,-110.75, 37.003201, -110.5, 37.004265, -110.469505, 36.998001,
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-110, 36.997967, -109.044571,36.999088, -109.045143, 37.375,
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-109.042824, 37.484692, -109.040848, 37.881176, -109.041405,38.153027,
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-109.041107, 38.1647, -109.059402, 38.275501, -109.059296, 38.5,
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-109.058868, 38.719906,-109.051765, 39, -109.050095, 39.366699,
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-109.050697, 39.4977, -109.050499, 39.6605, -109.050156,40.222694,
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-109.047577, 40.653641, -109.0494, 41.000702, -109.2313, 41.002102,
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-109.534233,40.998184, -110, 40.997398, -110.047768, 40.997696, -110.5,
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40.994801, -111.045982, 40.998013,-111.045815, 41.251774, -111.045097,
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41.579899, -111.045944, 42.001633, -111.506493, 41.999588,-112.108742,
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41.997677, -112.16317, 41.996784, -112.172562, 41.996643, -112.192184,
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42.001244,-113, 41.998314, -113.875, 41.988091, -114.040871, 41.993805,
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-114.038803, 41.884899, -114.041306,41, -114.04586, 40.116997,
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-114.046295, 39.906101, -114.046898, 39.542801, -114.049026, 38.67741,
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-114.049339, 38.572968, -114.049095, 38.14864, -114.0476,
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37.80946,-114.05098, 37.746284, -114.051666, 37.604805, -114.052025,
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37.103989)
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geometryWyoming = CreateGeometryObj(-111.045815, 41.251774, -111.045982,
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40.998013, -110.5, 40.994801, -110.047768, 40.997696, -110, 40.997398,
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-109.534233, 40.998184, -109.2313, 41.002102, -109.0494, 41.000702,
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-108.525368, 40.999634, -107.917793, 41.002071, -107.317177, 41.002956,
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-106.857178, 41.002697, -106.455704, 41.002167, -106.320587, 40.999153,
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-106.189987, 40.997604, -105.729874, 40.996906, -105.276604, 40.998188,
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-104.942848, 40.998226, -104.625, 41.00145, -104.052742, 41.001423,
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-104.051781, 41.39333, -104.052032, 41.564301, -104.052185, 41.697983,
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-104.052109, 42.001736, -104.052277, 42.611626, -104.052643, 43.000614,
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-104.054337, 43.47784, -104.054298, 43.503101, -104.055, 43.8535,
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-104.054108, 44.141102, -104.054001, 44.180401, -104.055458, 44.570877,
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-104.057205, 44.997444, -104.664658, 44.998631, -105.037872, 45.000359,
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-105.088867, 45.000462, -105.912819, 45.000957, -105.927612, 44.99366,
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-106.024239, 44.993591, -106.263, 44.993801, -107.054871, 44.996384,
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-107.133545, 45.000141, -107.911095, 45.001343, -108.248672, 44.999504,
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-108.620628, 45.000328, -109.082314, 44.999664, -109.102745, 45.005955,
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-109.797951, 45.002247, -110.000771, 45.003502, -110.10936, 45.003967,
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-110.198761, 44.99625, -110.286026, 44.99691, -110.361946, 45.000656,
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-110.402176, 44.993874, -110.5, 44.992355, -110.704506, 44.99239,
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-110.784241, 45.003021, -111.05442, 45.001392, -111.054558, 44.666336,
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-111.048203, 44.474144, -111.046272, 43.983456, -111.044724, 43.501213,
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-111.043846, 43.3158, -111.043381, 43.02013, -111.042786, 42.719578,
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-111.045967, 42.513187, -111.045944, 42.001633, -111.045097, 41.579899,
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-111.045815, 41.251774)
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geometryColorado = CreateGeometryObj(-109.045143, 37.375, -109.044571,
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36.999088, -108.378571, 36.999516, -107.481133, 37, -107.420311, 37,
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-106.876701, 37.00013, -106.869209, 36.992416, -106.475639, 36.993748,
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-106.006058, 36.995327, -105.717834, 36.995823, -105.220055, 36.995144,
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-105.154488, 36.995239, -105.028671, 36.992702, -104.407616, 36.993446,
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-104.007324, 36.996216, -103.085617, 37.000244, -103.001709, 37.000084,
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-102.986488, 36.998505, -102.759384, 37, -102.69767, 36.995132,
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-102.041794, 36.993061, -102.041191, 37.389172, -102.04113, 37.644268,
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-102.041695, 37.738529, -102.043938, 38.262466, -102.044113, 38.268803,
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-102.04483, 38.615234, -102.044762, 38.697556, -102.046112, 39.047035,
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-102.046707, 39.133144, -102.049301, 39.568176, -102.049347, 39.574062,
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-102.051277, 40.00309, -102.051117, 40.34922, -102.051003, 40.440018,
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-102.050873, 40.697556, -102.050835, 40.749596, -102.051155, 41.002384,
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-102.620567, 41.002609, -102.652992, 41.002342, -103.382011, 41.00227,
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-103.574036, 41.001736, -104.052742, 41.001423, -104.625, 41.00145,
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-104.942848, 40.998226, -105.276604, 40.998188, -105.729874, 40.996906,
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-106.189987, 40.997604, -106.320587, 40.999153, -106.455704, 41.002167,
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-106.857178, 41.002697, -107.317177, 41.002956, -107.917793, 41.002071,
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-108.525368, 40.999634, -109.0494, 41.000702, -109.047577, 40.653641,
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-109.050156, 40.222694, -109.050499, 39.6605, -109.050697, 39.4977,
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-109.050095, 39.366699, -109.051765, 39, -109.058868, 38.719906,
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-109.059296, 38.5, -109.059402, 38.275501, -109.041107, 38.1647,
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-109.041405, 38.153027, -109.040848, 37.881176, -109.042824, 37.484692,
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-109.045143, 37.375)
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# Insert rows for test states. If we were analyzing these geometries in Oracle
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# we would also add Spatial metadata and indexes. However in this example we
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# are only storing the geometries so that we load them back into Python, so we
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# will skip the metadata and indexes.
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print("Adding rows to table...")
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data = [
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('Nevada', geometryNevada),
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('Colorado', geometryColorado),
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('Wyoming', geometryWyoming)
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]
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cursor.executemany('insert into TestStates values (:state, :obj)', data)
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# We now have test geometries in Oracle Spatial (SDO_GEOMETRY) and will next
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# bring them back into Python to analyze with GeoPandas. GeoPandas is able to
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# consume geometries in the Well Known Text (WKT) and Well Known Binary (WKB)
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# formats. Oracle database includes utility functions to return SDO_GEOMETRY as
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# both WKT and WKB. Therefore we use that utility function in the query below
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# to provide results in a format readily consumable by GeoPandas. These utility
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# functions were introduced in Oracle 10g. We use WKB here; however the same
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# process applies for WKT.
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cursor.execute("""
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SELECT state, sdo_util.to_wkbgeometry(geometry)
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FROM TestStates""")
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gdf = gpd.GeoDataFrame(cursor.fetchall(), columns = ['state', 'wkbgeometry'])
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# create GeoSeries to replace the WKB geometry column
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gdf['geometry'] = gpd.GeoSeries(gdf['wkbgeometry'].apply(lambda x: loads(x)))
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del gdf['wkbgeometry']
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# display the GeoDataFrame
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print()
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print(gdf)
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# perform a basic GeoPandas operation (unary_union)
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# to combine the 3 adjacent states into 1 geometry
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print()
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print("GeoPandas combining the 3 geometries into a single geometry...")
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print(gdf.unary_union)
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