PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.

learn more… | top users | synonyms

1
vote
0answers
18 views

Import shapefiles into PostGIS using Python with psycopg2

I want to import shapefiles to PostGIS using Python with arcpy & psycopg2 to connect to PostGIS. I don't want to use the existing shapefile loader nor ogr, just write my own import tool. My steps ...
0
votes
1answer
35 views

Can't import shapefile to PostGIS

Sorry if my question is double post with the previous. I have tried to browse but I think I still can't find the solution. I am using postgresql 9.4.1 and postgis 2.1(pg 94) and also qgis 2.4.0. All ...
0
votes
1answer
16 views

Speeding Up pgr_dijkstra using bounding box in PostGis2.0

I'm using PostGIS for the first time to calculate distances between two points, for a driving school booking system I am working on. I have loaded in all of the maps for Australia, but the query I ...
0
votes
0answers
16 views

suitable column Data-type for geojson data storage and processign in PostGis

I have a MySQL table with 2 columns, id, a unique geometry id, and GeoJSON stored as a varchar, eg, {"type": "Point", "coordinates": [116.4, 45.2, 11.1]} ...
0
votes
1answer
25 views

Problem with importing WKT to PostGIS

I'm trying to import WKT (http://polygons.openstreetmap.fr/get_wkt.py?id=2413177&params=0 - boundary of one of districts of Łódź) into PostGIS database and convert it to geometry. I've created ...
1
vote
0answers
12 views

set Default projection in postgis table

I've set the SRID 4326 for a table having geometry column, but when i insert a geometry without SRID, i get an error because no SRID specified is interpreted as -1 or 0, so how i can set a default ...
1
vote
1answer
52 views

How to create dissolved buffers in QGIS with PostgreSQL/PostGIS?

Creating a dynamic buffer in QGIS I use the following query: CREATE VIEW buffer40units AS SELECT gid, st_buffer(geom,40)::geometry(polygon, 31492) AS geom FROM point; Now I want to dissolve ...
2
votes
0answers
21 views

ST_Buffer with segment AND endcap parameters

Making a QGis plugin that buffers a line and I want to declare a high number of segments and a flat endcap. ST_Buffer(geom, 40, 25, 'endcap=flat') This doesn't work with both parameters entered, ...
1
vote
1answer
41 views

Map-matching GPS points to the road network!

I am quite a newbie in Postgres and Postgis so please be simple and clear :) I am trying to do a simple map-matching (or path-inference if you wish) of some GPS points. I am using postgres(postgis). ...
0
votes
1answer
24 views

Displaying KML data with a user selection

I want to web map some historical cyclones data which are now in KML files, file/year. So I want the user to select a year from a button and the KML files will be displayed on interactive map). I ...
2
votes
1answer
52 views

Create common vertexes between shared polygon boundaries in PostGis?

Given two polygon tables L1 (blue) and L2 (red) that share a common boundary but different amount of vertexes, how can one make the shared boundary identical (they should share the same vertexes) ? ...
2
votes
1answer
38 views

Can't connect to foreign SQL Server table from PosgreSQL using OGR_FDW

I'm using Windows 7, with PostgreSQL 9.3.6 installed and PostGIS 2.1.5. While I wish I could get everything into PostgreSQL, I can't and need to connect to another server running SQL Server. I need to ...
0
votes
1answer
20 views

QGIS GPS not editing offline database

I have a set of layers from PostGIS that I have converted to offline. I am attempting to edit them via GPS. If the layer is point data, then I can add in that data without issue. However when I go to ...
0
votes
0answers
12 views

PostGis - ST_AsRaster returning raster smaller than reference raster

I am trying to convert a point geometry to a raster using a reference raster: SELECT ST_AsRaster(my_points, ref_raster) FROM my_table This works fine except it is only returning a subset of the ...
1
vote
1answer
28 views

PostGIS: Is it possible to identify overlapping polygons in the same layer using their geomteries?

I have a single table containing the geometries of ~3 million polygons and I am looking to calculate the number of polygons that overlap with another. I know that you are able to do this in QGIS ...
0
votes
1answer
23 views

QGIS add layer not working

I have QGIS 2.8. I open up the database manager, connect to PostGIS, and then execute a query. The resulting query has an id column, a name column, a geom column, and a membership column. I click on ...
1
vote
1answer
29 views

PostGIS and Mobile Devices Maps

I'm still learning the world of GIS reading this Introduction to PostGIS. So far I understand things but since I have an idea that I plan to later work on, I found something that I didn't quiet grasp. ...
0
votes
0answers
20 views

Point Cloud footprint/wireframe layer - PostGIS

I'm using PDAL to import LAS files into PostGIS. The tutorial provided by boundless is great, and shows how to display the data in patches, but it doesn't cover displaying the table 'footprint'. I ...
0
votes
0answers
11 views

WMS problems Qgis server with postgis

I have installed qgis and qgis server on a windows server. My plan is to use qgis server to generate a wms. It works fine when I'm using shape files in my qgis project, but when I'm adding a postgis ...
-2
votes
1answer
28 views

How can I select only the points in a mixed geometry column in postgis postgres

Table "public.eating_drinking" Column | Type | Modifiers --------+-------------------------+----------- osm_id | bigint | way | ...
1
vote
0answers
33 views

Calculate total line lengths within a polygon?

I have basically the same conundrum as How do i calculate line segment lengths within a polygon? but I'm working in PostGIS, not ArcGIS. Any pointers? This query seems to like it should work, just ...
0
votes
1answer
34 views

How do I calculate ST_Length in miles?

I am playing around with a map of bike lanes (so, lines) and trying to calculate the total number of miles of lane in each of a couple of regions. But I'm not even sure how to use ST_Length to ...
0
votes
0answers
29 views

How to import country administrative boundaries from OSM Planet to PostGIS Polygons

I need to import all world countries as polygons or multipolygons into PostGIS. Specifically, I need the administrative boundaries that are like this orange bubble around the actual land borders. ...
1
vote
1answer
22 views

PostGIS raster2pgsql problem

I ran into this problem in PostGIS: raster2pgsql -c -I -C -s 4326 -N -9999 -M -Y -F ./test2/*.tif rdem2 > rdem2.sql Processing 84/84: ./test2/dem2_4326_06_14.tif ERROR: ...
1
vote
1answer
45 views

Select points near polygon in Postgis

I'm trying to make a spatial query, but I think something is wrong with it: I have two tables, places (point) and cities (polygon) When I try to get the points within 500m to one point, there is no ...
1
vote
3answers
113 views

How to get extent of multiple geometries?

I can query a geometry extent like this: select ST_Extent(geom) from tableName; But sometimes I am querying geometries more than one. I am getting 5 points that different locations. So I wanto to ...
1
vote
1answer
28 views

I can't understand this ewkb type mask

I have the following ewkb strings from PostGIS: 01 01000020 E6100000 AECB9307F9D81240 0F2ADCE003704940 01 01000020 E6100000 7EAA0A0DC4920DC0 5AF0A2AF201F4440 I've been able to understand every data ...
0
votes
0answers
29 views

Find hotspot with highest density for two objects

I'm using PostgreSQL/PostGIS and I have an advanced type of query. My database contains two types of objects - let's say homes and crime. Is there a way that I can find the area with the densest ...
2
votes
0answers
28 views

How to create raster from table containing cell values in PostGIS?

I am having a table with integer values. These values are in between 0 and 2. I want to create a raster out of that table with integers as cell values. Or else how to create polygons out of that table ...
1
vote
1answer
22 views

QGIS Add PostGIS layer: restricting to single schema?

My primary PostGIS database has 12 schemas (schemae? TNIRN...), some of which have nasty-sized tables. The DB is on localhost, on my own machine. For the most part, the actual working tables are in ...
1
vote
1answer
30 views

POSTGIS query - extracting common point from polygon data

I have a polygon dataset and need to find the single common point where 3 polygons meet. I'm approaching this by creating duplicate tables and comparing them to the main one (polygon_table a). I've ...
1
vote
0answers
25 views

PostGIS Geography data type not displaying in QGIS

I am trying to display data held in the PostGIS Geography type on a map in QGIS. Whatever I do I can't get it to work. Here is the SQL that creates my data - a single point in London. CREATE TABLE ...
1
vote
0answers
51 views

How can I speed up a slow ArcGIS Server 10.2 - PostgreSQL (9.2) ST_Intersects query?

I am troubleshooting a slow st_geometry query in Postgres 9.2 that uses ST_Intersects--a basic Select from table where ST_Intersects type query. table_extent ...
1
vote
1answer
43 views

Postgis ST_Distance query returning inaccurate results

I am using the following query to retrieve records from a postgresql DB @services = Service.select("*, ST_Distance(services.lon_lat, ST_GeomFromText('POINT (lat lon)', 4326)) as ...
1
vote
0answers
50 views

GeoDjango: AttributeError: function 'GDALAllRegister' not found [closed]

Im trying to get started with GeoDjango. I am using this https://docs.djangoproject.com/en/1.8/ref/contrib/gis/tutorial/ tutorial. When I run "python manage.py migrate" This error occur: ...
0
votes
0answers
14 views

pgsql2shp query error select

I need to export from postgis some data obtaining the center of my polygons, now I'm working on Ubuntu. My command looks like this: ./pgsql2shp -f /home/me/ESTADOS_POINT -h localhost -p 5432 -P ...
1
vote
0answers
24 views

Mapnik performance - large polyline dataset

I'm working with a very large set of polylines - contour data - to be rendered with Mapnik. (The contours are generated using gdal_contour from SRTM data.) At present I'm storing them in PostGIS and ...
0
votes
2answers
27 views

SRID is messed up when google-maps layer is added

I've some problems with using a PostGIS layer within QGIS. First of all, I had this same problem on both QGIS 2.4.0 and 2.6.1 I cannot display the Google Maps layer AND my PostGIS layer together. ...
1
vote
1answer
79 views

Store a GeoJSON FeatureCollection to postgres with postgis

I am new to GeoJSON. I have a GeoJSON features collection as shown and would like to store it in postgres table (testtable). My postgres table has a serial id and geometry column. { "type": ...
3
votes
1answer
40 views

ST_MakeLine within CartoDB.js

I'm building an interactive map using CartoDB.js in an HTML page. I have the user input an address that gets geocoded. I then use the user's lat/lon coordinates to perform SQL queries on CartoDB. The ...
0
votes
2answers
36 views

Problem with a PostGIS trigger

I'm trying to update a lat and lon columns each time I insert a point with a trigger, but I don't know why I get an error. This is the syntax I'm writing: CREATE OR REPLACE FUNCTION update_tg2() ...
0
votes
1answer
49 views

pgrouting pgr_dijkstra forcing route along a selected edge?

I have routing working where a user clicks 2 points on the map, I find the closest vertex to those 2 clicked locations and pass that to a pgr_dijkstra function. What I would like is give the edge a ...
2
votes
1answer
46 views

Calculating Distances Between Geometry Columns of Differing SRIDs

I am attempting a relatively simple task but have been running into trouble. I have two tables, one which has lat and lon points which were geocoded using google (SRID 3857) and another table which ...
1
vote
0answers
12 views

Geoserver - How to make a psql-backed timestamp that uses timezones

I'm working on an application that extends geoserver and am frustrated as I'm trying to define a SimpleFeature that has timestamps that include timezones. I've tried declaring my timestamp field ...
0
votes
1answer
34 views

Plotting Street Map for City - Where do I start?

Please excuse my ignorance of this and if I break any of the rules please be gentle as this is my first post here and I'm not GIS expert either. I need people to steer me in right direction so that I ...
2
votes
0answers
23 views

Not able to get the PostGIS Layer Viewer running in pgAdmin or command line

I've installed PostGIS Layer Viewer as a plugin for pgAdmin. I've downloaded postgis_viewer.py from the official repository on GitHub! and followed the install instructions described on Web site!. ...
1
vote
0answers
29 views

I am getting error in PostGIS 'function st_clip(raster, integer, geometry) does not exist'? [closed]

I have to find the count of the number of pixels in a given band of a clipped raster. For clipping, I am using ST_clip(). Through clip function raster is clipped with a polygon. I am getting ...
1
vote
1answer
41 views

error importing shp into postgis using ogr2ogr

I run an automated script that copies a number shapefiles into PostGIS. I have a problem with one dataset which fails during the export. As the roads.shp dataset is maintained by someone else, I ...
1
vote
1answer
41 views

How to get pixel values/cell values for stored raster files in postgis?

Raster files in tiff format are storing into database.However I gets only an attribute table. Is there any way to retrieve pixel values/cell values in the table. I have used raster2pgsql command for ...
1
vote
1answer
85 views

Why doesn't my spatial index work?

I have a table with 50 million test points. The points are stored as latitude / longitude with SRID = 4326. The create script for the table: CREATE TABLE points ( name character varying, point ...