Hi, If I understand your question correct, yes I would like to break all lines in the intersections with another layer. No I have not tried MultiLinestrings comprised of all lines that are intersecting the lines to be broken. Don’t know how to do this. ☹
This is how far I have come: CREATE TABLE splittedlayer3 AS SELECT ST_CollectionExtract(ST_Split(o.the_geom, c.the_geom),2) as the_geom FROM "orgLayer" o, "cutLayer" c WHERE ST_Intersects(o.the_geom, c.the_geom) But this gives duplicate line segments when intersecting the cutting lines twice. /Paul Från: postgis-users [mailto:[email protected]] För Martin Davis Skickat: den 3 september 2019 19:18 Till: PostGIS Users Discussion Ämne: Re: [postgis-users] breake lines 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]<mailto:[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.
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