Good stuff, Simon.
So Jonathan, what behaviour are you actually seeing? Is an exception
being thrown, or does the output not match what you'd expect to see?
Simon Greener wrote:
Martin et al,
My first reaction to Jonathan's post and your question was to say that, no, Oracle
(as an OGC SFS and SQL/MM compliant product) does not support a "MultiPolygon
which
contains a MultiPolygon". I thought, though, that I should examine the actual
geometry in detail so I converted Jonathan's WKT geometry below back into an Oracle
SDO_GEOMETRY and examined its SDO_ELEM_INFO array. This is the result:
SDO_ELEM_INFO(1,1003,1,1743,2003,1,2041,2003,1,2071,1003,1,2779,2003,1)
This is: a simple polygon outer shell (1,1003,1) followed by 4 inner shells
(2003):
1743,2003,1,
2041,2003,1,
2071,1003,1,
2779,2003,1
Note that there is only 1 outer shell. Even if there were many outer shells
with each having many inner shells, the result would still be a single
multipolygon.
My test harness is after my salutation at the very end of this email.
regards
Simon
Date: Wed, 11 Feb 2009 11:24:23 -0800
From: Martin Davis <[email protected]>
Subject: Re: [jts-devel] jts-io mutipolygon
To: JTS Topology Suite Development <[email protected]>
Message-ID: <[email protected]>
Content-Type: text/plain; charset=windows-1252; format=flowed
Under the OGC SFS spec there is no such thing as a "MultiPolygon which
contains a MultiPolygon". Does Oracle actually support this?
If this is truly the case, I think you're seeing the workaround - JTS
maps the geometry to something which fits in its model. (Although this
situation was probably never designed for - I'm actually surprised that
it works).
Houde, Jonathan wrote:
Hi all,
I’ve been using jts-io to read geometries from oracle database.
I have a certain case where the geometry is a MultiPolygon which
contains MultiPolygon,
It seems that jts-io is not excepting this and doesn’t load it correctly.
It read the inner Multipolygon as single Polygon
You can see the geometry at the corresponding wkt geometry at the
bottom of my mail.
Any fix planned for that or possible workaround?
Thanks,
Jonathan
SDO_UTIL.TO_WKTGEOMETRY(GEOLOC) MULTIPOLYGON (((-71.33959188
46.81182897, -71.33935608 46.81166004, -71.33922 46.81155897,
-71.33990904 46.811142, -71.34054516 46.81077003, -71.34058512
--
Martin Davis
Senior Technical Architect
Refractions Research, Inc.
(250) 383-3022
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