[Django] #21273: Add read only support for Oracle XE to django.contrib.gis
Django
--------------------------------------+--------------------
Reporter: vinhussey | Owner: nobody
Type: Cleanup/optimization | Status: new
Component: GIS | Version: 1.4
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
--------------------------------------+--------------------
django.contrib.gis.backends supports Oracle but does not support the
spatial component of Oracle XE. Oracle XE has a more lenient licence than
Oracle and may be useful for accessing legacy spatial data.
Oracle XE may be accessed using cx_Oracle, but spatial data is not
converted into a usable form. The spatial data stored in oracle is
documented (search for 'oracle sdo_geometry').
The following is a short description of the point attribute - I will
expand with other types asap.
Example - Oracle spatial table named Floods with a spatial field geoloc:
{{{
>>> from import_data.models import *
>>> floods = Floods.objects.all()
>>> f = floods[99]
>>> g = f.geoloc
>>> g
<cx_Oracle.OBJECT object at 0xa02a3e0>
>>> dir(g)
['__class__', '__delattr__', '__doc__', '__format__', '__getattribute__',
'__hash__', '__init__', '__new__', '__reduce__', '__reduce_ex__',
'__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__',
'type']
>>> gtype = str(int(g.__getattribute__('SDO_GTYPE')))
>>> print gtype
2001
>>> gdims = gtype[0]
>>> gdims
'2'
>>> gtopo = gtype[1]
>>> gtopo
'0'
>>> ggeomtype = gtype[2:]
>>> ggeomtype
'01'
>>> gsrid = g.__getattribute__('SDO_SRID')
>>> gsrid
82086.0
>>> gpoint_x = g.__getattribute__('SDO_POINT').X
>>> gpoint_y = g.__getattribute__('SDO_POINT').Y
>>> gpoint_z = g.__getattribute__('SDO_POINT').Z
>>> print gpoint_x, gpoint_y, gpoint_z
162913.389524 340748.357977 None
>>> g_ewkt = "SRID:%s:POINT(%f %f)" %
(str(int(g.__getattribute__('SDO_SRID'))),
g.__getattribute__('SDO_POINT').X, g.__getattribute__('SDO_POINT').Y)
>>> g_ewkt
'SRID:82086:POINT(162913.389524 340748.357977)'
}}}
From the Oracle docs, this is a 2 dimensional (gdims), null topology
(gtopo), POINT geometry, srid = 82086 (Irish Grid), with x and y co-
ordinates and null z coordinates.
Further information is stored in other attributes for more complex
geometries - a very wide range is available. For a point, these may not
necessarily be used.
{{{
>>> print g.__getattribute__('SDO_ELEM_INFO')
None
>>> print g.__getattribute__('SDO_ORDINATES')
None
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/21273>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: vinhussey | Owner: nobody
Type: | Status: new
Cleanup/optimization | Version: master
Component: GIS | Resolution:
Severity: Normal | Triage Stage:
Keywords: | Unreviewed
Has patch: 0 | Needs documentation: 1
Needs tests: 1 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by vinhussey):
* cc: vinhussey (added)
* needs_docs: => 1
* version: 1.4 => master
* needs_tests: => 1
* needs_better_patch: => 0
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:1>
Django
Reporter: vinhussey | Owner: nobody
Type: | Status: new
Cleanup/optimization | Version: master
Component: GIS | Resolution:
Severity: Normal | Triage Stage:
Keywords: | Unreviewed
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by vinhussey):
= Correction to WKT in example =
{{{
>>> g_ewkt = "SRID=%s;POINT(%f %f)" %
(str(int(g.__getattribute__('SDO_SRID'))),
g.__getattribute__('SDO_POINT').X, g.__getattribute__('SDO_POINT').Y)
>>> g_ewkt
'SRID=82086;POINT(162913.389524 340748.357977)'
}}}
= Note on SRID =
Before version 10, Oracle used it's own SRIDs. The sample is Irish Grid
1965, this corresponds to EPSG:29903.
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:2>
Django
Reporter: vinhussey | Owner: nobody
Type: | Status: new
Cleanup/optimization | Version: master
Component: GIS | Resolution:
Severity: Normal | Triage Stage:
Keywords: | Unreviewed
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by vinhussey):
= Polygon example =
{{{
>>> from import_data.models import *
>>> f = Floods.objects.get(flood_id=305)
>>> g = f.geoloc
>>> g
<cx_Oracle.OBJECT object at 0xaee2b40>
>>> dir(g)
['__class__', '__delattr__', '__doc__', '__format__', '__getattribute__',
'__hash__', '__init__', '__new__', '__reduce__', '__reduce_ex__',
'__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__',
'type']
>>> gtype = str(int(g.__getattribute__('SDO_GTYPE')))
>>> print gtype
2003
>>> gdims = gtype[0]
>>> gdims
'2'
>>> gtopo = gtype[1]
>>> gtopo
'0'
>>> ggeomtype = gtype[2:]
>>> ggeomtype
'03'
>>> gsrid = g.__getattribute__('SDO_SRID')
>>> gsrid
82086.0
>>> gpoint_x = g.__getattribute__('SDO_POINT').X
>>> gpoint_y = g.__getattribute__('SDO_POINT').Y
>>> gpoint_z = g.__getattribute__('SDO_POINT').Z
>>> print gpoint_x, gpoint_y, gpoint_z
158775.736744 155058.070105 None
>>> print g.__getattribute__('SDO_ELEM_INFO')
[1.0, 1003.0, 1.0]
>>> print g.__getattribute__('SDO_ORDINATES')
[158851.770034052, 155240.090599927, 158814.553479071, 155238.39040849303,
158783.91910735102, 155236.430187781, 158758.984345447, 155234.259943421,
158738.883116615, 155231.929681045, 158722.73284741, 155229.469404029,
158709.667461087, 155226.92911800402, 158698.804384201, 155224.358828602,
158689.277540007, 155221.79854032502, 158680.352825359, 155219.268255426,
158671.914763359, 155216.767973906, 158663.96335400498, 155214.267692386,
158656.539839049, 155211.747408614, 158649.652466839, 155209.197121463,
158643.32598242702, 155206.57682643, 158637.58513086, 155203.866521262,
158632.438160491, 155201.056204833, 158627.918064717, 155198.11587376602,
158624.04958859, 155195.035526933, 158620.865725509, 155191.805163209,
158618.39946887302, 155188.424782593, 158616.692060433, 155184.874382835,
158615.768245238, 155181.153963933, 158615.652768339, 155177.253524761,
158616.395119835, 155173.17306532, 158618.003548075, 155168.882582232,
158620.436811311, 155164.382075495, 158623.645419442, 155159.631540607,
158627.55513731902, 155154.61097531402, 158632.12472319198,
155149.29037623902, 158637.28819026198, 155143.659742256,
158642.98780007902, 155137.689069986, 158649.174062542,
155131.33835492402, 158655.789239203, 155124.62759932398,
158662.800336662, 155117.58680656302, 158670.166113169,
155110.32598902902, 158677.853575324, 155102.895152351, 158685.846226427,
155095.384306664, 158694.094576378, 155087.863459851, 158702.573880129,
155080.42262204702, 158711.24289592798, 155073.131801134,
158720.07687872602, 155066.061004995, 158728.98509667302,
155059.20023250402, 158737.893314621, 155052.539482534, 158746.727297419,
155046.078755086, 158755.388064868, 155039.788046781, 158763.809630169,
155033.677358746, 158771.901261471, 155027.716687602, 158779.58872362602,
155021.896032223, 158786.80602983403, 155016.205391483, 158793.569676794,
155010.604760877, 158799.912657907, 155005.064137029, 158805.876214922,
154999.54351543201, 158811.493341239, 154994.002891583, 158816.805278607,
154988.41226210402, 158821.853268778, 154982.73162249, 158826.66205679902,
154976.930969363, 158831.289381122, 154970.970298219, 158835.77648349598,
154964.859610184, 158840.19759907, 154958.60890638301, 158844.626962994,
154952.228187944, 158849.11406536802, 154945.737457118, 158853.73314134,
154939.136713904, 158858.55017771202, 154932.45596168202,
158863.631161282, 154925.695200452, 158869.009085451, 154918.884433591,
158874.650956818, 154912.14367461202, 158880.474291883, 154905.612939281,
158886.42135219803, 154899.42224223702, 158892.417902613,
154893.70159811902, 158898.397956328, 154888.581021566, 158904.279029843,
154884.220530595, 158910.00338471, 154880.730137593, 158915.488537428,
154878.219854946, 158920.61076274802, 154876.67968153, 158925.22159037,
154876.05961171302, 158929.180798347, 154876.329642117,
158932.36466142803, 154877.41976486, 158934.624709315, 154879.30997768903,
158935.812471708, 154881.930272722, 158935.812471708, 154885.260647707,
158934.525729116, 154889.23109476102, 158932.11721093, 154893.79160825402,
158928.80962259902, 154898.86217917703, 158924.825669573,
154904.382800774, 158920.379808949, 154910.283465161, 158915.70299452601,
154916.484163331, 158911.009683404, 154922.92488852702, 158906.52258103,
154929.52563174098, 158902.414902754, 154936.23638734102,
158898.703145276, 154943.01715082402, 158895.379060246, 154949.857921063,
158892.39315756303, 154956.70869242802, 158889.745437229, 154963.56946492,
158887.39465749302, 154970.410235159, 158885.324321655, 154977.190998642,
158883.501436316, 154983.901754242, 158881.91775312502, 154990.532500833,
158880.581520433, 154997.11324179402, 158879.492738239,
155003.71398500798, 158878.667903244, 155010.39473723, 158878.123512147,
155017.195502965, 158877.867813299, 155024.19629122101, 158877.909055048,
155031.437106504, 158878.271982446, 155038.977955568, 158878.940098792,
155046.86884404602, 158879.80617553703, 155055.11977306302,
158880.754735782, 155063.74074374398, 158881.653805926, 155072.721754965,
158882.37966072198, 155082.07280785, 158882.80857492, 155091.793902401,
158882.81682327, 155101.885038616, 158882.280680523, 155112.34621649698,
158881.09291813, 155123.24744392498, 158879.204045991, 155134.878753557,
158876.597567406, 155147.600185932, 158873.24048897598, 155161.771781588,
158869.0998173, 155177.753581065, 158864.167304029, 155195.895623776,
158858.39345906302, 155216.557950259, 158851.770034052, 155240.090599927]
>>> e_wkt = 'SRID=%s;POLYGON((' %
(str(int(g.__getattribute__('SDO_SRID'))))
>>> for i in range(len(ords)/2):
... e_wkt = e_wkt + '%f %f' %(ords[2*(i-1)+2], ords[2*(i-1)+3])
... if i != len(ords)/2 - 1:
... e_wkt = e_wkt + ','
... else:
... e_wkt = e_wkt + '))'
...
>>> print e_wkt
SRID=82086;POLYGON((158851.770034 155240.090600,158814.553479
155238.390408,158783.919107 155236.430188,158758.984345
155234.259943,158738.883117 155231.929681,158722.732847
155229.469404,158709.667461 155226.929118,158698.804384
155224.358829,158689.277540 155221.798540,158680.352825
155219.268255,158671.914763 155216.767974,158663.963354
155214.267692,158656.539839 155211.747409,158649.652467
155209.197121,158643.325982 155206.576826,158637.585131
155203.866521,158632.438160 155201.056205,158627.918065
155198.115874,158624.049589 155195.035527,158620.865726
155191.805163,158618.399469 155188.424783,158616.692060
155184.874383,158615.768245 155181.153964,158615.652768
155177.253525,158616.395120 155173.173065,158618.003548
155168.882582,158620.436811 155164.382075,158623.645419
155159.631541,158627.555137 155154.610975,158632.124723
155149.290376,158637.288190 155143.659742,158642.987800
155137.689070,158649.174063 155131.338355,158655.789239
155124.627599,158662.800337 155117.586807,158670.166113
155110.325989,158677.853575 155102.895152,158685.846226
155095.384307,158694.094576 155087.863460,158702.573880
155080.422622,158711.242896 155073.131801,158720.076879
155066.061005,158728.985097 155059.200233,158737.893315
155052.539483,158746.727297 155046.078755,158755.388065
155039.788047,158763.809630 155033.677359,158771.901261
155027.716688,158779.588724 155021.896032,158786.806030
155016.205391,158793.569677 155010.604761,158799.912658
155005.064137,158805.876215 154999.543515,158811.493341
154994.002892,158816.805279 154988.412262,158821.853269
154982.731622,158826.662057 154976.930969,158831.289381
154970.970298,158835.776483 154964.859610,158840.197599
154958.608906,158844.626963 154952.228188,158849.114065
154945.737457,158853.733141 154939.136714,158858.550178
154932.455962,158863.631161 154925.695200,158869.009085
154918.884434,158874.650957 154912.143675,158880.474292
154905.612939,158886.421352 154899.422242,158892.417903
154893.701598,158898.397956 154888.581022,158904.279030
154884.220531,158910.003385 154880.730138,158915.488537
154878.219855,158920.610763 154876.679682,158925.221590
154876.059612,158929.180798 154876.329642,158932.364661
154877.419765,158934.624709 154879.309978,158935.812472
154881.930273,158935.812472 154885.260648,158934.525729
154889.231095,158932.117211 154893.791608,158928.809623
154898.862179,158924.825670 154904.382801,158920.379809
154910.283465,158915.702995 154916.484163,158911.009683
154922.924889,158906.522581 154929.525632,158902.414903
154936.236387,158898.703145 154943.017151,158895.379060
154949.857921,158892.393158 154956.708692,158889.745437
154963.569465,158887.394657 154970.410235,158885.324322
154977.190999,158883.501436 154983.901754,158881.917753
154990.532501,158880.581520 154997.113242,158879.492738
155003.713985,158878.667903 155010.394737,158878.123512
155017.195503,158877.867813 155024.196291,158877.909055
155031.437107,158878.271982 155038.977956,158878.940099
155046.868844,158879.806176 155055.119773,158880.754736
155063.740744,158881.653806 155072.721755,158882.379661
155082.072808,158882.808575 155091.793902,158882.816823
155101.885039,158882.280681 155112.346216,158881.092918
155123.247444,158879.204046 155134.878754,158876.597567
155147.600186,158873.240489 155161.771782,158869.099817
155177.753581,158864.167304 155195.895624,158858.393459
155216.557950,158851.770034 155240.090600))
}}}
Note we are losing precision with the %f (6 decimal places, down from 12).
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:3>
Django
Reporter: vinhussey | Owner: nobody
Type: | Status: new
Cleanup/optimization | Version: master
Component: GIS | Resolution:
Severity: Normal | Triage Stage:
Keywords: | Unreviewed
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by vinhussey):
= Example model =
models.py
{{{
from django.db import models
class Floods(models.Model):
flood_id = models.IntegerField(primary_key=True)
...
geoloc = models.TextField(blank=True)
}}}
= Settings =
This example used django core, not django.contrib.gis
settings.py
{{{
DATABASES = {
'remote': {
'ENGINE': 'django.db.backends.oracle', # Add
'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'.
'NAME': 'XE', # Or path to database file if
using sqlite3.
...
},
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:4>
Django
Reporter: vinhussey | Owner: nobody
Type: Cleanup/optimization | Status: new
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Changes (by timo):
* stage: Unreviewed => Accepted
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:5>
Django
Reporter: vinhussey | Owner: nobody
Type: Cleanup/optimization | Status: new
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by anonymous):
Added an initial class that generates wkt for POINT (tested), LINESTRING
(not tested yet), POLYGON (tested).
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:6>
Django
Reporter: vinhussey | Owner: nobody
Type: Cleanup/optimization | Status: new
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by vinhussey):
Attached 2 files:
* Sample data
* Updated code (version 4)
To test this file:
{{{
import sys
from oracle_xe_geom.models import Sdo_Test
from oracle_xe_geom.test_oracle_xe_class import sdo_geometry
def main(argv=None):
if argv is None:
argv = sys.argv
usage = "usage: %prog [options] arg"
data = []
geoms = []
sd = Sdo_Test.objects.all()
for s in sd:
data.append(s)
g = sdo_geometry(s.geom)
geoms.append(g)
print s.id, g.wkt
print data
if __name__ == "__main__":
sys.exit(main())
main()
}}}
Result:
{{{
1 POINT(200000.000000000000 200000.000000000000)
2 LINESTRING(200000.000000000000 200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000 220000.000000000000)
0 [1.0, 1003.0, 1.0]
3 POLYGON((200000.000000000000 200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000,200000.000000000000
220000.000000000000,200000.000000000000 200000.000000000000))
0 [1.0, 1003.0, 1.0]
1 [11.0, 2003.0, 1.0]
4 POLYGON((200000.000000000000 200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000,200000.000000000000
220000.000000000000,200000.000000000000
200000.000000000000)(202000.000000000000
202000.000000000000,208000.000000000000
208000.000000000000,208000.000000000000
202000.000000000000,202000.000000000000 202000.000000000000))
5 MULTIPOINT(200000.000000000000 200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000,200000.000000000000 220000.000000000000)
0 [1.0, 2.0, 1.0]
1 [9.0, 2.0, 1.0]
6 MULTILINESTRING((200000.000000000000
200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000,200000.000000000000
220000.000000000000)(202000.000000000000
202000.000000000000,208000.000000000000
208000.000000000000,208000.000000000000 202000.000000000000))
0 [1.0, 1003.0, 1.0]
7 MULTIPOLYGON(((200000.000000000000
200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000,200000.000000000000
220000.000000000000,200000.000000000000 200000.000000000000)))
0 [1.0, 1003.0, 1.0]
1 [11.0, 2.0, 1.0]
2 [17.0, 1.0, 1.0]
[[1003], 2, 1] [['200000.000000000000
200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000,200000.000000000000
220000.000000000000,200000.000000000000 200000.000000000000'],
'200000.000000000000 200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000 220000.000000000000',
'210000.000000000000 210000.000000000000']
8 GEOMETRY(POLYGON((200000.000000000000
200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000,200000.000000000000
220000.000000000000,200000.000000000000
200000.000000000000)),LINESTRING(200000.000000000000
200000.000000000000,220000.000000000000
200000.000000000000,220000.000000000000
220000.000000000000),POINT(210000.000000000000 210000.000000000000))
9 POLYGON(([[200000.0, 200000.0], [200000.0, 200000.0], [200000.0,
200000.0], [200000.0, 200000.0], [200000.0, 200000.0]]))
10 POLYGON(([[200000.0, 200000.0], [220000.0, 200000.0], [220000.0,
220000.0]]))
[<Sdo_Test: point>, <Sdo_Test: linestring>, <Sdo_Test: polygon>,
<Sdo_Test: polygon with inner ring>, <Sdo_Test: multi point>, <Sdo_Test:
multi line>, <Sdo_Test: multi polygon with 1 ring>, <Sdo_Test: geometry
collection - polygon and point>, <Sdo_Test: rectangle - 2 points>,
<Sdo_Test: circle - 3 points>]
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:7>
Django
Reporter: vinhussey | Owner: nobody
Type: Cleanup/optimization | Status: new
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by shai):
Hi Vincent,
I am far from being a !GeoDjango expert; in fact, I only started looking
into it recently. I usually handle Oracle issues, but I don't use Oracle
XE currently, and am not sure exactly how much spatial functionality is
available on XE. I took a look at your latest code, and I have some
comments.
First of all, the general scope of the work: As far as I could see, what
you have added is a class for interpreting the SDO_GEOMETRY type; do you
intend to also support other operations, such as geometric queries? Are
they supported on XE? If not, the best integration into Django seems to be
a custom field type.
Second, technical details:
The most glaring point in your code is the explicit use of
`__getattribute__`: This is a "magic method" in Python, it implements
attribute access. You should be able to replace every occurrence of
`self.geometry.__getattribute__('NAME')` with `self.geometry.NAME`, for
every `NAME`.
The second is -- instead of trying to generate the WKT yourself, it seems
better to use GEOS objects -- WKT generation is already implemented there,
as long as a ton of other functionality. The GEOS objects are explained
[https://docs.djangoproject.com/en/1.6/ref/contrib/gis/geos/ here].
So -- the right thing to achieve, apparently, is a custom field, which
inherits `TextField` and interprets the object it gets as a GEOS object. I
haven't looked into the !GeoDjango (Oracle backend) code, but perhaps you
can extract some code from there which will help you; I'd be a little
surprised if SDO_GEOMETRY objects themselves are much different between
Oracle XE and Standard.
Hope this helps,
Shai.
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:8>
Django
Reporter: vinhussey | Owner: nobody
Type: Cleanup/optimization | Status: new
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by vinhussey):
Hi Shai,
Thanks for the constructive comments. I have changed from the explicit
use of `__getattribute__` as suggested.
The reason for taking this approach is that Oracle XE does not provide a
WKT function. See these comments in
https://github.com/django/django/blob/master/django/contrib/gis/db/backends/oracle/operations.py
{{{
"""
This module contains the spatial lookup types, and the
`get_geo_where_clause`
routine for Oracle Spatial.
Please note that WKT support is broken on the XE version, and thus
this backend will not work on such platforms. Specifically, XE lacks
support for an internal JVM, and Java libraries are required to use
the WKT constructors.
"""
...
class OracleOperations(DatabaseOperations, BaseSpatialOperations):
compiler_module = "django.contrib.gis.db.backends.oracle.compiler"
name = 'oracle'
oracle = True
valid_aggregates = {'Union', 'Extent'}
Adapter = OracleSpatialAdapter
Adaptor = Adapter # Backwards-compatibility alias.
area = 'SDO_GEOM.SDO_AREA'
gml = 'SDO_UTIL.TO_GMLGEOMETRY'
centroid = 'SDO_GEOM.SDO_CENTROID'
difference = 'SDO_GEOM.SDO_DIFFERENCE'
distance = 'SDO_GEOM.SDO_DISTANCE'
extent = 'SDO_AGGR_MBR'
intersection = 'SDO_GEOM.SDO_INTERSECTION'
length = 'SDO_GEOM.SDO_LENGTH'
num_geom = 'SDO_UTIL.GETNUMELEM'
num_points = 'SDO_UTIL.GETNUMVERTICES'
perimeter = length
point_on_surface = 'SDO_GEOM.SDO_POINTONSURFACE'
reverse = 'SDO_UTIL.REVERSE_LINESTRING'
sym_difference = 'SDO_GEOM.SDO_XOR'
transform = 'SDO_CS.TRANSFORM'
union = 'SDO_GEOM.SDO_UNION'
unionagg = 'SDO_AGGR_UNION'
# We want to get SDO Geometries as WKT because it is much easier to
# instantiate GEOS proxies from WKT than SDO_GEOMETRY(...) strings.
# However, this adversely affects performance (i.e., Java is called
# to convert to WKT on every query). If someone wishes to write a
# SDO_GEOMETRY(...) parser in Python, let me know =)
}}}
Once we have WKT, we can use geos, so thanks for that tip.
Vincent
Replying to [comment:8 shai]:
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:9>
Django
Reporter: vinhussey | Owner: nobody
Type: Cleanup/optimization | Status: new
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 1
Easy pickings: 0 | UI/UX: 0
Comment (by jtiai):
SDO_GEOMETRY itself has been same for a good while. I do have almost
working version of read/write support for Oracle XE, as well as 3D support
for Oracle geometries in general.
There exists few peculiarities between versions, specially between 10g and
11g and 3d geometries.
Currently I think that backend I've been working on is only failing is
some coordinate transformations.
--
Ticket URL: <https://code.djangoproject.com/ticket/21273#comment:10>