Questions tagged [spatial-query]
A query for geometric features based on their spatial relationship.
202 questions
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Quickly make server side spatial filters for WFS layers based on other layer's selected geometries in QGIS
In QGIS 2.12.1, I have a WFS layer which is huge so I don't want my users to load it entirely but only parts of it based on intersections with geometries.
Today, I'm using the query builder and ...
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Performing a Spatial Query in a loop in PyQGIS
What I am trying to do: loop through a point shapefile and select each point that falls into a polygon.
The following code is inspired by a spatial query example I found in a book:
mitte_path = r"D:\...
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Using qgis:selectbylocation in PyQGIS
I am trying to use the processing toolbox to perform a spatial query (points in polygon). I am not sure how to use the tool and I keep getting this Error:
Wrong number of parameters.
Here is my ...
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Remove islands and completely surrounded polygons after polygonization with QGIS
I have a line map of buildings in a city. I was able to correctly polygonize the buildings in QGIS with the Polygonize processing algorithm. All the holes/islands became features as expected. Now I ...
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Query across layers of SHP files?
I would like to query features from a SHP vector that intersect with features from another vector.
Pseudocode:
"Name" IS intersects( countries)
How would be the valid query composed?
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0
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1
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How to use intersection in spatial guery in postgresql?
I want to get id, time and point_metric columns from intersection between two geometry(geom_lines and gem_houses). I wrote following sql code, however it fore an error (argument of WHERE must be type ...
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Spatial Query: The query from "LayerName" using "FID" in field not possible
In QGIS Wien, I am performing a spatial query with two layers (points and buffer areas) and receive the following error when creating a new layer with intersecting features: The query from "LayerName" ...
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SQL and ArcGIS data querying: what's the difference?
I am wondering if the language used by ArcGIS for data querying (e.g., search by attribute) is part of the SQL language, or to what extent there is a connection between the two (and where does it come ...
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PostGIS 3D bounding box query that envolves all 3 axes (xyz)
I have some experience with PostgreSQL, but not with PostGIS, and for the life of me I can't make my bounding box take the Z axis into account.
I have a points table with XYZ columns. I add another ...
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Number of Neighbors Around a Point
I need to get a count of neighbors within 100m for each point in a set of 250 million points. The result would have the id of each point accompanied by the number of neighbors around them. Can this be ...
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Running spatial query on huge table [duplicate]
I've got two tables conatining geometry: 1 containing big polygon's (regions, srid=4326) and another containing smaller polygon's (pand, srid=28992, containg ~9.9milion rows)
By using one of the big ...
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Help with sub-queries PostgreSQL [closed]
I wish to ask for some advice when it comes to building nested spatial expressions in PostgreSQL. I end up with the same kind of problem many times when it comes to select more than one type of ...
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PostGIS: Strategy for fastest select by BBox with an ORDER BY polygon area clause. Cluster?
Update 2 (below) suggests 14% of the table geometries are stored out-of-line with the rest of the table records. This may be a useful clue.
The Problem:
We've got a table with appx 170,000 WGS84 ...
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2
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ArcGIS Javascript Spatial Query with Lat Lng or X Y?
I am using Google Maps on the front end as all I need on this view is to show the points. When user clicks on the map in the view, it selects a point hence giving out lat and lng. I am trying to use ...
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Extracting data from four intersecting polygon layers in PostGIS?
I've been using the following code in PostgreSQL/PostGIS for the last year, as needed, which is about once a quarter. It works OK, it's just that it takes days to run. With over 25,000 parcels making ...
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Performing Boundary Select and Sum Attributes in QGIS? [closed]
I´m a MapInfo user, I´ve gone over to QGIS and it´s got a lot going for it, except for some "missing" simple features from MapInfo I just can´t do without.
MapInfo Boundary Select - spatial query on ...
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PostGIS ST within does not exist
I'm quite new to postgresql and postgis so this error will probably due to some rookie mistake.
I want to run the spatial query ST_within. When I describe the query like this
SELECT nw.entity_id AS ...
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2
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0
answers
81
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Select a polygon which is just partly member of another polygon with its area of the other polygon
I need to generate random points within geometries, which works quite good, but there are some small errors. Take the picture below. There are some greenish and redish Polygons(?!) which do not have ...
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7
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2
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Find start of river
Edit: Follow-up question here (= Find headwater polygons).
How can I determine the start of a river in PostGIS?
I have a river network (Multiline) and want to find the startpoints of the rivers.
I ...
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1
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562
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How to show a map with queries from a map file connected to postgres in browser using javascript?
So, the problem is how to show a map in browser using JavaScript.
I have a map file with 2 layers in it: "peta" is a shp data from PostGIS and "korban" is a numeric data from PostgreSQL, and then I ...
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12
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2
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448
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Identify points in a shapefile that have no other point within x km with QGIS
This is probably a naive question but I am struggling as a new user to QGIS.
I have a very large shapefile (275,000 points, but can break this into about 10 subregions if necessary for faster ...
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2
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1
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219
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Get feature data from lat long input QGIS
In QGIS, I have a polygon dataset with feature data. I would like to extract data from this dataset using a latitude and longitude.
To be more clear, I have a list of 1000 coordinates. I would like ...
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How to run spatial query get fields value of 2 layers?
Last month I asked vb.net arcobjects spatial query get fields value of desired layer only.
Now there is some change in the requirement, I need to get value of 2 layers after use "Select Features" ...
- 933
2
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3
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drawing concentric circles in arcmap 10.1
I am using ArcMap 10.1 and I would like to know if there is a way to draw circles at a specific distance from a georeferenced coordinate. I have a property and I would like to know how far you can ...
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Spatial queries to find co-occurrences of POIs
Given a POI database containing different types of points, e.g. hospital and pharmacy, how can I select the locations where a hospital and a pharmacy are closer than a certain threshold (e.g. 1000m)?
...
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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 ...
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2
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vb.net arcobjects spatial query get fields value of desired layer only
Currently I am using ArcObjects (10.2.1) in vb.net (vs 2012). What I intent to develop is a spatial query tool. There are 2 steps in the function:
(1) Use "Select Features" tool in ArcMap to select ...
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Counting number of points/lines/polygons contained within polygon when feature to count is from server?
I'm currently running a study where I need to query the number of points/lines/polygons that are contained within a project boundary - intersecting lines and polygons need to be counted as well. The ...
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How do you create a query that will result with the adjacent parcels?
I have a shapefile with parcel data, and I am trying to create a query that will render a list or something similar that will list adjacent parcels to a specific parcel.
I want to be able to select ...
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1
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Get the width and height of a rectangular polygon in PostGIS
I have a table with point features saved in the my PostgreSQL database, and I can run the following query to get the extent of the point features and I turned the extent back into a geometry:
SELECT ...
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Selecting Counties within Region via Spatial Query using QGIS/PostGIS?
I'm using GQIS 2.2 and PostGIS on Postgresql 9.3.
I have 5 regions in the contiguous United States. Each region has states, and each state has counties. I would like to think that the data I'm given ...
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3
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2
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794
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How to do simple self join and touches function in postgis?
I am having trouble with this query and neighbor calculation in PostGIS. I want to find out which are the neighbors of Sweden in the table COUNTRIES which has column 'the_geom' for geometry and '...
0
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1
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How can I find the segment of a line that lies within a polygon using Postgis?
Given a "road", represented by a line, that crosses a "state", represented by a polygon:
What is the SQL query I can use to find the segment of the road that is within the state?
A concrete example.
...
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1
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833
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ST_Within from centroid of geometry
I am looking at doing a spatial query where I can find when the center of one feature falls within another. For example, when the center (centroid) of a building falls within a grid tile. I know I can ...
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1
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Problem PostGIS Spatial Query ST_Contains ST_Disjoint ST_Intersects
I'm working on a project with two different tables inside a database. One contains points in a column geometry(Point,4326) type and the second one has a column geometry(MultiPolygon,4326). Now I would ...
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0
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76
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Count gaps between polygon in spatialite
I have a database (.db) with a table that contains thousands of polygons containing id and geometry. I like a query that can get me the 'number of errors where there are gaps between polygons".
How ...
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2
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691
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Is it possible to run a spatial query in QGIS 2.0 across multiple layers using a user-specified radius from a point?
I would like to be able to click on a point on a map to select all vector features (from multiple layers) within a specified radius of the point. Can anyone point me in the direction of how to do this ...
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1
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349
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Running loop in query in PostGIS
I am new to PostGIS.
I have a table of buildings each having a value for number of people living in it. I would like to calculate the total value (sum of number of people) in all buildings which ...
- 449
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2
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642
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1
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0
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172
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PoI Range query
I have a dataset of 100,000 PoIs represented by (id, name, longitude, latitude)..
I would like to perform a large number (around 10,000) search operations on this dataset. each search operation ...
-1
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1
answer
751
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How to run Spatial Query using ArcGIS for Desktop?
I have a shapefile of a forest inventory of the uk. I want to find out the total area of woodland within a 60km radius of a specific point. I have added a layer for the point and added a 60 km buffer. ...
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0
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Find area with highest relative density of one type of object
I'm using PostgreSQL/PostGIS and I have an advanced type of query.
My database contains two types of object - let's say pubs and churches :)
Is there a way that I can find the area with the densest ...
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19
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1
answer
12k
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What is difference between ST_DWithin and ST_Distance for proximity search in PostGIS?
I have records stored in a table with latitude/longitude coordinates stored in a geometry field. I want to find all records nearby a user supplied reference point. Note "nearby" probably means less ...
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959
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Adding MSSQL spatial layer using Python
I'm having difficulty adding a MSSQL spatial data layer using Python. The database is password protected, and I can add the layer without any problems using the built in feature, but I can't make it ...
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4
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2
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6k
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Postgis, get the points that are x meters near another point, in meters
I'm trying to find the points within a certain distance, in meters, from another point.
I'm using the function ST_Buffer, but I don't get how to express the distance in meters.
I'm trying with ...
- 275
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3
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3k
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QGIS spatial join, calculating distance from polygon to point layer
I am trying to perform a kind of 'spatial join' in Arcgis, joining to a polygon layer atributes of the closest feature of a point layer, as well as distance. But 'spatial query' doesn't offer an ...
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geoprocessing across multiple vector layers QGIS2
I have 6 layers of point data (each layer is one year), where data in each layer are distributed throughout a grid, and the grid is identical in each layer. I'd like to extract data from each layer, ...
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2
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Best way to figure out which regions a point is in a shapefile?
I'm trying to figure out the best way on Android to figure out if a point in region as defined in a shapefile. For instance, I might want to know what country I'm in using the Geo Common's Shapefile ...
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1
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PHP/MySQL, PostgreSQL spatial queries. Find a polygon that contains a coordinate? [closed]
I am building a non mapping javascript app and I am wanting to take a lat/long coordinate and query a MySQL table of polygons for the one that contains the point.
I have looked into MySQL spatial ...
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4
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1
answer
12k
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spatial query st_contains postgis
This seems too simple to be asking this but I am really new to PostGIS/Postgres have been going around in circles with this. I am performing a really simple spatial query where I would like to make a ...
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