PostGIS

问题 I have detailed US county maps, from the TIGER LINE data sets. How might I sample, smooth, or degrade the data so that I get straighter, more boxy, less "noisy" shapes to represent the geographical features -- in this case just county boundaries and state lines, but maybe also in the general case? The sampling could happen at rendering time if that can be done efficiently, or a parallel data set could be generated and stored. I am using PostGIS, and the lines are multi-polylines generated by

问题 I have import OpenstreetMap data into Postgres with gis extension with tool osm2pgsql (-s option) of course, I have the following tables planet_osm_point planet_osm_ways .... Within planet_osm_ways I have a column called way, type geometry(LineString, 4326), content like following

问题 Fellows, I already had a really hard time trying to make a migration from a postgis 1.5 to 2.3. Actually I had many attempts to do that with all version of postgis: 2.0, 2.1, 2.2 and now 2.3. As I have spent a few weeks with that, and as I am ready to drop that I keep using my old version of postgresql and postgis, I hope my question finds a echo somewhere... I only want to migrate one table field, a geometry field. So before trying to do that, I would like to hear if any of you have

问题 I am trying to execute a parametrised query from C# and I get the error: ERROR: XX000: parse error - invalid geometry with the hint "POLYGON((:m" <-- parse error at position 11 within geometry But when I run the query in pgAdmin III replacing the parameters with their values the query works. The code is command.CommandText = "SELECT area_code FROM area WHERE ST_INTERSECTS(ST_GeographyFromText('POLYGON((:minx :miny, :minx :maxy, :maxx :maxy, :maxx :miny, :minx :miny))'), shape) AND area_type

问题 Everything worked fine, but some time ago rails app response a error. PG::UndefinedFile: ERROR: could not access file “$libdir/postgis-2.1": No such file or directory Also now I can't create database backup, it's crashed on table which working whit postgis. Backup will creating if exclude this table. pg:psql -c "\dx postgis" postgis 2.1.7 I tried to find a solution to this problem and what I found was: ALTER EXTENSION postgis UPDATE; ALTER EXTENSION postgis_sfcgal UPDATE; ALTER EXTENSION

问题 I have built a docker container from docker hub with : docker run --name some-postgis -e POSTGRES_PASSWORD=mysecretpassword -d mdillon/postgis docker run -it --link some-postgis:postgres --rm postgres \ sh -c 'exec psql -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres' An inspect : $ docker inspect b89c7f54e76a [ { "Id": "b89c7f54e76aa82bd142e1eb45a1f12008bf2ee2f94e392b08b386493b58891f", "Created": "2017-08-08T14:34:02.375576229Z", "Path": "docker-entrypoint.sh"

问题 I'm trying to setup a basic working postgis setup with python ppygis package. >>> import psycopg2 >>> import ppygis >>> connection = psycopg2.connect(database='spre', user='postgres') >>> cursor = connection.cursor() >>> cursor.execute('CREATE TABLE test (geometry GEOMETRY)') >>> cursor.execute('INSERT INTO test VALUES(%s)', (ppygis.Point(1.0, 2.0),)) >>> cursor.execute('SELECT * from test') >>> point = cursor.fetchone()[0] >>> print point 0101000000000000000000F03F0000000000000040 >>> I

问题 I need to read a postgis geometry column as wkt using nHibernate. I know I could use nHibernate Spatial, but that is not an option in my case. I have seen this post: Best way to map a hidden property in NHibernate (fluent) where the wkt is stored in another column and he uses triggers to update the actual geometry. However the project owners do not want to have an extra column for this purpose. I found this thread as well: Use PostGIS columns transparently in Hibernate, but no has provided an

问题 I got some strange behavior of combined generate_series. In 2 different polygons that I tried to fill with a grid, one grid was much rarer: The query was like this: SELECT osm_id , generate_series(floor(st_xmin(way))::int, ceiling(st_xmax(way))::int, 150) x, generate_series(floor(st_ymin(way))::int, ceiling(st_ymax(way))::int, 150) y from osm_polygon order by osm_id, x, y; I tried tracing the problem, and just entered min/max coordinates. Generate series from min/max values create correct

问题 I'm currently using Flyway to manage migrations on an application which uses Postgis (PostgreSQL geospatial extension). This plugin uses a table called spatial_ref_sys which is located in the same schema the application uses too, when I call mvn flyway:clean I'm getting an error indicating that Flyway was unable to delete this table (it was created using user postgres); if I change the owner to my application database user, then the error changes to: ERROR: cannot drop table spatial_ref_sys