St_node could work with a collection. I guess the collection could have the two geometries. A.
Il mar 3 set 2019, 19:36 Martin Davis <[email protected]> ha scritto: > If I'm understanding the requirement correctly, the problem with ST_Node > is that it accepts a single geometry and nodes all lines in that geometry. > > It sounds like what's required is an ST_Node variant which would accept > two arguments: a target geometry and a noding geometry. The target > geometry would be noded against the noding geometry, and then returned > without incorporating any additional linework from the noding geometry. > > On Tue, Sep 3, 2019 at 10:22 AM Andrea Peri <[email protected]> wrote: > >> Hi, >> I will a chance trying to use the ST_Node. >> >> A. >> >> >> >> >> Il mar 3 set 2019, 19:18 Martin Davis <[email protected]> ha scritto: >> >>> Have you tried using ST_Split passing each input line and for the second >>> argument a MultiLineString comprised of all lines that it might intersect >>> (obtained via BBOX or ST_Intersects query)? It seems like that should not >>> create any duplicate linework from the input line. >>> >>> As far as I know there's no other way to do this using current PostGIS >>> functions. It's an interesting requirement - it sounds like essentially >>> you want to node one layer against another. There's actually the machinery >>> to do this internally in PostGIS/GEOS, but it's never come up as a >>> requirement before, so has not been exposed as a function. >>> >>> What is your use case? >>> >>> On Tue, Sep 3, 2019 at 9:48 AM <[email protected]> wrote: >>> >>>> If I split lines with another line layer, I will get a lot of >>>> duplicaded line segments since the lines could be intersected several >>>> times. It is not possible to use update on the table when splitting one >>>> geomety to two. >>>> I think it must be possible, but I’m not that skilled in SQL and I’ve >>>> not found any examples on the net. >>>> >>>> >>>> _______________________________________________ >>> postgis-users mailing list >>> [email protected] >>> https://lists.osgeo.org/mailman/listinfo/postgis-users >> >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> https://lists.osgeo.org/mailman/listinfo/postgis-users > > _______________________________________________ > postgis-users mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/postgis-users
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