1
vote
1answer
15 views

How to get the data type of each column from a postgis table

I need to get the column data types of all columns in a table, including the geometry types. What I wanted to know is if there is a function or SQL that gives something like this: column_name | ...
1
vote
0answers
35 views

PyQGIS Dialog Plugin not resetting

I have written a PostGIS search plugin that works pretty well, except two things that I just cannot figure out a solution 1) When the dialog closes and then is reopened the previous query is still in ...
0
votes
2answers
24 views

How can I optimize this point-linking query?

I have the following query, and am wondering how it could be optimised to run faster: WITH gps_nodes_1 AS ( SELECT "NODE_ID", "geog" FROM gps_nodes WHERE ST_Distance("geog",ST_GeogFromText('POINT( ...
0
votes
1answer
22 views

How can I combine two datasets with the same schema in to one table?

So I have two tables (in CartoDB/PostGIS) that are from two tiger shapefiles that have the exact same attributes, just in different counties. I want to combine them in to a single table, just ...
0
votes
2answers
38 views

sql query to get origins and destinations

I have a table of cities with an ID and geometry (200K rows) and a table of travels, with only two ID: idfrom, idto (7K rows) I'm wondering how could I select the geometries for each one in order to ...
1
vote
2answers
73 views

How can I create a hexbin layer using the SQL and CartoCSS parameters in cartodb.js?

CartoDB has a great hexbin visualization wizard baked into the client dashboard: However, I like using cartodb.js to customize events and interactions; in particular, I'd like to make styles ...
-1
votes
1answer
92 views

Shortest Path Dijkstra

I would like to calculate the shortest path with dijkstra algorithm. sample query SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_dijkstra(' SELECT gid AS id, ...
0
votes
1answer
52 views

How to cut/split multipolygon with blade (linestring) into two pieces using PostGIS? [closed]

I struggle to do split operation in postgis I tried to build a query but Im always fail. Id like to cut a multipoligon with a blade (a linestring) into two pieces. These two objects have specific ...
1
vote
1answer
26 views

Rewrite query to match two points with a linestring in a different database table

OK, not sure if I've worded the title brilliantly, but here goes: Suppose I have: a table "gps_nodes" containing columns: "EASTING" (containing longitude data) "NORTHING" (containing latitude ...
3
votes
1answer
152 views

PostGIS intersection function

I have a problem with intersection function. I built my query following http://manual.linfiniti.com/en/postgis/geometry.html, 5.7 section. I made my clip object, a red linestring frame: But after ...
1
vote
1answer
49 views

Calculating difference between bearing values in degrees

Suppose I have 3 geographic points, A, B and C. I can calculate the bearing of B from A (in degrees) using this SQL snippet: degrees(ST_Azimuth(geogA,geogB)) as brg_a_b ...and the same of C from ...
4
votes
2answers
220 views

SQL Syntax to extract (convert) Strings with Degrees Minutes to Decimal Degrees

I have a PostgreSQL/PostGIS database with a two string fields containing Lat and Long coordinates in degrees and decimal minutes, like this 45° 24.5' N 3° 43.01' E. How can I convert them into ...
3
votes
1answer
46 views

Use selected value in postgis function

How can I use the selected value from a SELECT statement in a PostGIS function. e.g. using the geom_way from SELECT geom_way FROM osm_2po_4pgr ORDER BY ST_Distance(ST_GeomFromText('POINT(21.323329 ...
4
votes
2answers
238 views

Import large CSV file into PostGIS

I am trying to import CSV files into PostGIS. Following this post, I have created tables before. I found other suggestions saying that I can run the copy command. If I run this command: COPY table ...
1
vote
1answer
72 views

Trouble with INSERT in PostgreSQL 9.1

I am trying to execute the following: INSERT INTO lithic (cp_east, cp_north, type, material, art_count, comment, field_no, gps_unit, initials, rec_date, cortex, geom) SELECT (cp_east, cp_north, ...
2
votes
2answers
64 views

shp2pgsql mangles date field — quotes data as if it were char or varchar

I'm attempting to import a shapefile into postgis via shp2pgsql. Among the fields in the shapefile's .dbf file is a date field with format yyyymmdd, which is a valid date format for postgresql. ...
0
votes
1answer
40 views

Issues with pgrouting workshop code in postgis 2.11/pgrouting 2.0

I'm having issues getting the pgrouting workshop to work on Postgresql 9.2/PostGIS 2.11 and pgrouting 2.0 on windows. How can I rewrite the following php/sql code and make it compatible with my ...
0
votes
1answer
285 views

Postgresql Trigger to insert records in my table from another one

I spent few days trying to resolve this question but it was impossible. I have two tables: Table1. CREATE TABLE point ( id_point integer NOT NULL DEFAULT, layer text, elevation numeric, ...
0
votes
1answer
172 views

Postgis: find geometry within multiple polygons

I've got two tables with geometry in it. Table 1:items holds items with a point geometry; while the second table property_zones holds polygons. The Items: CREATE TABLE public.items ( id integer ...
2
votes
1answer
80 views

How to split polygons with another polygon and inheritage data?

Let's say that we have two tables with polygons representing areas. Table A and Table B. Geometries from table A represents both the valid and invalid areas. And the geometries in table B represents ...
2
votes
1answer
70 views

Tiger geocoder / postgis - get county from point

Looking for some help with getting the county for a lat / lon. I have postgis / tiger geocoder installed and can reverse look up a point and get the addresses. I would like to get the county the ...
1
vote
1answer
101 views

Three table postgres sql join query

I'm having trouble getting my SQL query to work with three tables. I'm new to SQL to I've already spent considerable time trying to understand the documentation and making some sense of it. I'm using ...
1
vote
0answers
49 views

How do I make vectorlayer with sql on PostGis via python code

I need to make a vectorLayer and fill with the SQL's results on PostGIS via python code. I'm working with python 2.7, QGIS 1.8 and PyQt 4.5 How do I it ? thanks
2
votes
0answers
54 views

What is the MS SQL Spatial syntax for counting points within polygons? [duplicate]

All, What I'm trying to do is this: Count points within polygons There are thousands of points and maybe 2 dozen polygons Get a list back of the 2 dozen polygons by name and the count of points ...
1
vote
2answers
559 views

How to select all points within a circle in PostGIS?

I have set of points in a PostGIS Table (Type Geometry). Now, I need to filter points that lie in a circle with a center (C) and radius (R)! I expect C to be of type Point or Coordinates.. R to be ...
1
vote
2answers
456 views

How to connect Dotspatial with PostGIS/PosgresSQL database and perform SQL function

I am currently doing a project that needs a GIS front-end interface to visualize geographical objects (road networks), and a back-end geo-spatial database to implement network analysis (SQL based). ...
2
votes
1answer
183 views

How to merge connected lines with same direction (PostGis)

I am looking for a way to join all lines that are connected, have the same direction, i.e. start point of one is end point of the other, and share some common attributes. In fact, I want to connect ...
5
votes
2answers
476 views

What are benefits of using ArcGIS with PostgreSQL over simply ArcSDE?

I understand that in order to benefit from ArcGIS spatial datatypes (ST_GEOMETRY, versioned geodatabases etc.) ArcSDE needs to be installed - and with the 10.1 client it is automatically installed ...
2
votes
1answer
455 views

How to get polygons from PostGIS table to PHP array best?

Currently I fetch polygons from a database table using ST_AsText(). The results are in text format, like the following. POLYGON((84 104,212 48,321 122,243 179,275 238,131 240,84 104)) I am not ...
0
votes
2answers
643 views

Cannot insert simple geometry data

I installed PostgreSQL 9.2.4 and PostGIS 2.0.3 on my Windows 8 machine. Then I created a table using phpPgAdmin and added a geometry column using the following statement. SELECT ...
1
vote
0answers
265 views

PostGIS Better ST_Intersects Query

I am currently using the following queries to return all features that intersect a large and complex polygon. I initially tried to use a single ST_Intersect query but because the number of features it ...
1
vote
1answer
157 views

SQL Command to convert pgRouting result to GeoJSON

My goal is to produce a Web UI for pgRouting using this tutorial. I have already imported my data from an OSM pBF to PostGIS using osm2po. Using the pgRoutingLayer plugin for QGIS, I was able to ...
0
votes
1answer
245 views

ST_Box2D in PostGIS 2.0

I am getting an error trying to create a bounding box of a geometry using ST_Box2D(). Is the function deprecated? If so, what is the equivalent function? SELECT ST_Box2D(ST_GeomFromText('LINESTRING(1 ...
1
vote
2answers
262 views

Function for Selecting Points in a Polygon

I've been banging on this for a few hours, but since I'm relatively new to PostgreSQL and PostGIS, I can't find the solution. I'm trying to create a stored procedure (function) which will return all ...
3
votes
1answer
170 views

Given a lat/long point, determine if it's land or water?

I have a PostGIS-enabled PostgreSQL 9.1 installation with the 10M physical dataset from Natural Earth imported. It's been converted to 900913, and in QGIS I can visualize the data. So the plumbing's ...
3
votes
2answers
143 views

Traversing a PostGIS table tree

I'm developing a geospatial db for a company that operates at a number of large facilities. Its primary purpose is to help staff locate themselves and equipment within each facilities' multi-storey ...
4
votes
2answers
295 views

PostGIS stored procedures

I am wondering if there are open source applications that make extensive uses of the special functions (the ST_* stored procedures) provided by PostGIS? I found many apps that support storing map data ...
1
vote
1answer
78 views

How to get routes in the database that intersects circle?

I have routes (linestrings) recorded in the database. I want to create a query which returns the routes that have some commonality with a circle whose center and radius are passed as parameter. I ...
3
votes
1answer
413 views

Routing with multiple points

I am using postgreSQL, postGIS and pgrouting. Now I am really confused on how am I going to find the shortest path between multiple points. I know how to find it between two points through dijkstra ...
6
votes
2answers
771 views

PostGIS SQL query to find a polygon that intersects with a line

I need to build a PostGIS query that would select every polygon inside an area the river is flowing through. I'd better describe with an example below: There is a river (blue line) flowing through ...
1
vote
1answer
153 views

What are FLOOR and CEILIING in PostGIS designated for?

Just a short question to lighten up my understanding of some PostGIS-code: Regarding the creation of user-defined grids I often find the expressions CEILING and FLOOR. Like in this non-representative ...
2
votes
1answer
128 views

Problem with SPIT (error while importing layers to POSTGIS)

I was attempting to import a polyline roads layer into postgis, using both SPIT in QGIS 1.7 and postGIS GUI for this purpose. I have received errors through both processes as described here: SPIT ...
1
vote
0answers
377 views

How to handle postgresql/postgis geometry type errors in a function?

I have created the following function in PL/SQL to make a polygon from a set of linestrings: CREATE OR REPLACE FUNCTION _myfunction( _fid integer, _rid integer ) RETURNS VOID AS $$ ...
2
votes
1answer
206 views

How to return nearest point to input lat/long with distance?

I am trying to write a query with PostGIS that returns one row where the geometry of that row is the closest to an input point. I would also like to include the distance between these points in the ...
3
votes
1answer
80 views

PostGIS - improving sql statement

I've managed to create the below statement that creates a table based on a point in polygon query. However it creates a column that gives a true/false value which I then delete out all the f values ...
6
votes
1answer
270 views

Join based on maximum overlap in PostGIS/PostGresQL?

I have two sets of polygons in two tables. The sets overlap each other. For each polygon in set A, I would like to get the ID of the polygon in set B that it overlaps the most. I'm using PostgreSQL ...
6
votes
0answers
414 views

Getting ST_Difference between two different tables in postgis [closed]

One table has a series of grid squares in it, and the other has millions of voronoi polygons in it. I need to create a table that has the difference between the two of the them so that I effectively ...
1
vote
1answer
209 views

Why is my PostGIS transformation not working?

I am using a PostGIS query to find the intersection of two streets, and then transform the results into lat/lon. The street database's current SRID is 6856, a projection I added to PostGIS myself; and ...
2
votes
1answer
145 views

How to create a network with all the track points

I have created a sample network through the use of gps visualizer. Than I used the ogr2ogr function to import this data in my database. Now I have a table which holds all the track points of these ...
6
votes
1answer
316 views

Clarification of Logical Operators in a PostGIS Database

The following query returns this result: select count(*) from a , b where a.geom && b.geom; count ------- 66514 On a postgis 2 database. What does the logical operator AND ...