2
votes
1answer
26 views

Spatial joining syntax

A standard PostGIS point-in-polygon query might look like this. (example tutorial) SELECT p.*,b.polyname FROM points p, shapes s WHERE ST_Within(p.the_geom,s.the_geom) Imagine this was not a ...
2
votes
1answer
44 views

How to find a nearest line to a point

I have a table with many points that need to be associated with street segments to calculate an average value. should I do a relationship for all points to a street segment that is closest. I have ...
4
votes
1answer
43 views

How to select random adjacent census tract

I have set of census tracts spaced out across a city and I would like to randomly choose an adjacent census tract to explore nearby demographic data. I'm not sure if there is an easy process for ...
2
votes
1answer
57 views

Error at or near “select” PostGIS

I'm using node.js to connect to a PostGIS database to check if an input feature significantly intersects with an existing feature. The error seems to be with the nested SELECT statement - can anyone ...
0
votes
0answers
41 views

PostGIS Spatial query taking a very long time

I'm trying to return a count of crimes (points) that occur in each police grid (polygons), as well as the geometry data, but the query takes ~22 seconds. This seems oddly high and will be problematic ...
1
vote
1answer
24 views

Remove inner polygons postgis

I'm trying to remove inner polygons with postgis. I've created a routine, that resumes in: From a polygon table, with a unique id: -Create a linestring table from polygon -Import to postgis -Get the ...
1
vote
1answer
44 views

Postgis create polygon extent/convex hull from spatial table

Please help, I have a polygon layer representing building footprints. I want to create new view in postgis that will contain rectangle representing bounding box and also another view that will have ...
1
vote
1answer
49 views

SQL-query should return GeoJSON FeatureCollection

I'm trying to return a GeoJSON FeatureCollection object from a SQL-query with PostgreSQL 9.3 and PostGIS 2.1. This is my query so far: SELECT row_to_json(fc) AS p FROM (SELECT 'FeatureCollection' ...
0
votes
0answers
20 views

time complexity of selected algorithm - SQL

I use PostGIS - SQL 1) I need know time complexity of algorithm which in I use these functions: ST_Equals, ST_Overlaps, ST_Distance_Spheroid and ST_Dwithin Is a time complexity diferent when I use ...
1
vote
1answer
78 views

PostgreSQL/PostGIS: create spatial view

I have a polygon layer and a point layer. 1) I wrote a spatial query to count how many points fall in each polygon: SELECT polR.codeR, count(pntAZ.geom) as tot_pntAZ FROM boundaryR as polR LEFT ...
0
votes
1answer
33 views

I need to test a condition within the sql in postgis.

I need to test a condition within the sql in postgis. My sql: SELECT (zoneamento3_32722.zt3), logradouros32722."NMIDEABR", logradouros32722."OBJECTID", ...
0
votes
2answers
40 views

How to join data in postgis tables to form layer with subset of attributes

In QGIS I am trying to join data from two postgis tables. I can not figure out how to do this at sql because add layer tools seem to allow one to select just one table to filter on. Instead I ...
0
votes
0answers
29 views

Postgresql (soln would be basic SQL I think): ORDER by distance to a point and return those distances in array pairs w/ the full records

so I know there have been some questions asked about how to calculate distance using postgis and how to order results by their distance from a respective point. I'm not very talented at SQL (at all) ...
0
votes
1answer
23 views

PGrouting encapsulated queries error [quotes problem]

I'm facing a quote problem on a pgrouting query. What I'm thinking is wrong is that my query only works if I use one, then four, then eight quotes on encapsulated queries. Is there a way to simplify ...
1
vote
2answers
80 views

adding geometries to a source, target table for multiple rows in pgrouting

I am having an issue trying to perform the pgr_dijkstra algorithm and getting back a line in my table for multiple rows. I have a table that has a columns of source, target node id's but I cannot ...
2
votes
2answers
99 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
78 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
33 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
37 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
51 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
98 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
139 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
83 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
47 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
361 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
108 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
469 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
59 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
745 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
262 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
86 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
49 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
625 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
319 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
90 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
86 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
114 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
52 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
55 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
870 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
578 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
257 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 ...
6
votes
2answers
618 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
541 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
928 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
428 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 ...
2
votes
1answer
186 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
354 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
339 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
189 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 ...