Contents
Can you store topological elements in PostGIS topology?
Please refer to PostGIS Topology section of manual for details. With topology support enabled you can store topological elements , define TopoGeometry objects as being composed by these elements, convert TopoGeometry objects to simple Geometry objects to use all functions defined on the latter.
Is there a way to enable PostGIS support?
In order to enable PostGIS support you need to be equipped with the following: Move under the topology/ directory and run: No C libs involved so far, so no need to make install. To uninstall/disable just drop the ‘topology’ schema. It contains all the objects installed by the topology.sql script (remember to cascade).
How to create a polygon schema in PostGIS?
I have created a topology schema ‘parcele_topo’ with the default tables edge_data, face, node and relation. I also imported a polygon shapefile to this schema using shp2pgsql-gui as table ‘parcele_tsur_116’.
How to check the validity of a topology?
To verify validity of a topology: The return set will contain references to elements involved in the invalidity. You currently need to explicit call the TopoGeometry=>Geometry cast function. This will probably be made implicit when the code is more tested: Tests are included under the topology/test directory.
How to return deleted rows in PostgreSQL table?
To return the deleted row (s) to the client, you use the RETURNING clause as follows: DELETE FROM table_name WHERE condition RETURNING (select_list | *) Code language: SQL (Structured Query Language) (sql) The asterisk (*) allows you to return all columns of the deleted row from the table_name.
Where to find Entity Relationship Diagram in PostGIS?
An entity-relationship diagram of the topology concepts can be found in the SVN repository of PostGIS (trunk), under the topology/ER/ directory . The SVN repository also contains initial code, being a set of definitions and pl/pgsql functions. A README file therein contains usage and test notes.