Hi, I can confirm this serious issue, see
http://hub.qgis.org/issues/8174 > Dear Paolo, > > I just notice this behavior a few days ago. Right now I can reproduce this > problem: > Using Qgis to draw polygons on a clean Postgis layer with "Avoid > Intersections" turned on and check every time I create a new polygon, this > is the number of polygons until an over-lap is detected: 4, 7, 6, 15, 7 > > My postgis layer creation sql: > CREATE TABLE polygon_layer > ( > id serial primary key, > geom geometry(MultiPolygon,3857), > ); > CREATE INDEX polygon_layer_idx > ON polygon_layer > USING gist > (geom); > > Over lap detecting sql: > select a.id, b.id > from > polygon_layer as a > inner join > polygon_layer as b > on st_overlaps(a.geom, b.geom) > where a.id < b.id; > > My system versions: > Client: Qgis 1.8 on Debian 7 64 bit > Server: Postgis 2.0 on PosgreSQL 9.2, Ubuntu 12.04 64 bit > > Thanks. > > > 2013/6/26 Paolo Cavallini <[email protected]> > >> Il 26/06/2013 05:04, Cao Minh Tu ha scritto: >> >> > My question is: Is there an easier way to make Qgis "Avoid >> intersections" plays well >> > with Postgis "st_overlaps" so I can avoid the other dreaded way? >> >> Dear Cao, >> I did not notice this problem for PostGIS layers. Could you please be more >> specific >> (which version of qgis? when exactly do you encounter this issue?). If >> confirmed, >> better solve it upstream, in qgis code, than fix it with ad hoc solutions >> (pg triggers). _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
