Hi, 1. I advanced ...and I used the topology.toTopoGeom() and now the relation is populated.
2. I try to understand the following join *pe.parcelle** p1 on (1, (p1.topo).id) *= (r1.layer_id, r1.topogeo_id) the second part of the join is clear -- comes from the relation table however the first part - is not so clear according to you - "parcelle is the polygon table with a topo column containing the TopoGeometry object corresponding to the polygon" (you have used here pe.parcelle - is it the table name ? ) so if in my case I have table 'department' with column 'topogeom' it would look like department d1 on (1,(d1.topogeom).id) = (r1.layer_id, r1.topogeo_id) ? Ofer On Mon, Feb 9, 2015 at 3:52 PM, Ofer Zilberstein <zilberstein.o...@gmail.com > wrote: > Hi Nicolas, > > 1. I used ST_CreateTopoGeo() to build the topology (not the > topology.toTopoGeom() > as you mentioned ) > > When I look at the relation table its empty ? should I use > topology.toTopoGeom() > instead, and it will populate it ? > > 2. can you explain what the parentheses (special the 1, ...) part mean... > > join pe.parcelle p1 on *(1, (p1.topo).id)* = (r1.layer_id, r1.topogeo_id) > > Thanks in advanced ... > > Ofer > > On Mon, Feb 9, 2015 at 11:05 AM, Nicolas Ribot <nicolas.ri...@gmail.com> > wrote: > >> Hi, >> >> As usual with SQL, there must be several other ways to perform the same >> query. >> >> As the edge view stores 2 faces id per row (left and right), I duplicated >> the joins to join both left_face and right face against the original >> polygon table (p1 and p2 aliases) >> >> Nicolas >> >> On 8 February 2015 at 21:57, Ofer Zilberstein <zilberstein.o...@gmail.com >> > wrote: >> >>> Much Thanks, >>> >>> First I will try to understand the join that you did and then try to >>> implement it... >>> >>> Ofer >>> >>> On Sun, Feb 8, 2015 at 12:44 PM, Nicolas Ribot <nicolas.ri...@gmail.com> >>> wrote: >>> >>>> Hi, >>>> >>>> When you build the topology, for instance with topology.toTopoGeom(), >>>> you get back a TopoGeometry object for each polygon added to the topology. >>>> This TopoGeometry is used to keep a link between your polygon object >>>> and all the topological elements composing it. >>>> The "relation" table inside the topo schema holding the topology >>>> contains the identifier of the topoGeometry object and the identifiers of >>>> topo elements composing the polygon. >>>> >>>> To get the right and left original polygons from the topology, you make >>>> a join between edge, relation and pg table: >>>> (topo_grass is the topo schema, parcelle is the polygon table with a >>>> topo column containing the TopoGeometry object corresponding to the >>>> polygon): >>>> >>>> select e.edge_id, e.left_face, e.right_face, >>>> p1.id as left_id, p2.id as right_id >>>> from topo_grass.edge e >>>> join topo_grass.relation r1 on r1.element_id = e.left_face >>>> join pe.parcelle p1 on (1, (p1.topo).id) = (r1.layer_id, r1.topogeo_id) >>>> join topo_grass.relation r2 on r2.element_id = e.right_face >>>> join pe.parcelle p2 on (1, (p2.topo).id) = (r2.layer_id, r2.topogeo_id); >>>> >>>> Nicolas >>>> >>>> >>>> >>>> On 8 February 2015 at 10:29, Ofer Zilberstein < >>>> zilberstein.o...@gmail.com> wrote: >>>> >>>>> >>>>> Hi, >>>>> >>>>> When you build topology from set of connected polygons, the original >>>>> polygon attributes are not part of the topology model. The model creates >>>>> MBR face for each original polygon. >>>>> >>>>> The edges hold the left & right faces. >>>>> >>>>> How or what is the right way to add to the edges the right and left >>>>> original polygons ? >>>>> >>>>> -- >>>>> >>>>> *Ofer Zilberstein* >>>>> >>>>> Mobile: 972-544886873 >>>>> >>>>> Skype: ofer.zilberstein >>>>> >>>>> Mail: zilberstein.o...@gmail.com >>>>> >>>>> _______________________________________________ >>>>> postgis-users mailing list >>>>> postgis-users@lists.osgeo.org >>>>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >>>>> >>>> >>>> >>>> _______________________________________________ >>>> postgis-users mailing list >>>> postgis-users@lists.osgeo.org >>>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >>>> >>> >>> >>> >>> -- >>> >>> *Ofer Zilberstein* >>> >>> Mobile: 972-544886873 >>> >>> Skype: ofer.zilberstein >>> >>> Mail: zilberstein.o...@gmail.com >>> >>> _______________________________________________ >>> postgis-users mailing list >>> postgis-users@lists.osgeo.org >>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >>> >> >> >> _______________________________________________ >> postgis-users mailing list >> postgis-users@lists.osgeo.org >> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >> > > > > -- > > *Ofer Zilberstein* > > Mobile: 972-544886873 > > Skype: ofer.zilberstein > > Mail: zilberstein.o...@gmail.com > -- *Ofer Zilberstein* Mobile: 972-544886873 Skype: ofer.zilberstein Mail: zilberstein.o...@gmail.com
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