thanks, got it. Surely you may meet this issue, distinct cannot find the 'OPERATOR =' for data type 'box2d'.
PostGIS only supports 3 kinds of OPERATOR =, i.e., 1. OPERATOR = (geometry,geometry) 2. OPERATOR = (geography,geography) 3. OPERATOR = (raster,raster) Maybe we can try these ways: 1. cast box2d to geometry: select distinct st_extent(the_geom)::geometry from test; 2. create ordering operator for box2d. Cheers, Kuien Liu On Tue, Apr 21, 2015 at 6:06 PM, Nick Ves <[email protected]> wrote: > On Tue, Apr 21, 2015 at 12:50 PM, Kuien Liu <[email protected]> wrote: > > I'm not sure I understand what your query really looks like, but I can > run > > query below. > > try this one: > > select distinct st_extent(the_geom) over () from test; > > > > gis=# SELECT ST_GeometryType(ST_Extent(the_geom))='ST_Polygon' FROM test > > WHERE num < 10; > > ?column? > > ---------- > > true > > (1 row) > > > > where the table 'test' contains 50,000 points. > > > > Wish this helps to you. > > > > Cheers, > > Kuien Liu > > > > On Tue, Apr 21, 2015 at 4:58 PM, Nick Ves <[email protected]> wrote: > >> > >> I was playing with the ST_Extent today and I wanted to try a query like > >> this: > >> > >> select distinct ST_Extent(geom) over () box from parcels_test > >> > >> where the geom is Type ST_Polygon but I got this error instead: > >> > >> ERROR: could not identify an equality operator for type box2d > >> > >> The aim was to get the BBox from a set of polygons that might or might > >> not be adjutant. Ofc you can get the same results by limit the result > >> to 1 but, it hitted me strange box2d type not having an equal operator > >> > >> using "POSTGIS="2.1.4 r12966" GEOS="3.4.2-CAPI-1.8.2 r3921" PROJ="Rel. > >> 4.8.0, 6 March 2012" GDAL="GDAL 1.11.1, released 2014/09/24" > >> LIBXML="2.9.1" LIBJSON="UNKNOWN" RASTER" > >> _______________________________________________ > >> postgis-users mailing list > >> [email protected] > >> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > > > > > > > > _______________________________________________ > > postgis-users mailing list > > [email protected] > > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >
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