Questions tagged [query]

A command used to retrieve information from a database

Filter by
Sorted by
Tagged with
0 votes
1 answer
11 views

Web AppBuilder DE - Use an uploaded shapefile to query

The shapfile is zipped and uploaded through the "Add Data" widget. I am looking to use an customized widget to read the feature layer from the upload and query another feature layer. Since ...
user avatar
  • 331
0 votes
1 answer
29 views

Wrong polygons displayed in QGIS spatial query

I have two polygons, one is a virtual layer that generates a buffer around a site, the other is a set of polygons representing locations of interest. I have tried to create a query that gives me only ...
user avatar
1 vote
1 answer
29 views

Reviewing query from which Virtual Layer was originated in QGIS

I created a Virtual Layer by going in Layer > Add Layer > Add or Edit Virtual Layer. This new layer was created by building a query on another layer I had in my project. Ho can I check, ...
user avatar
1 vote
0 answers
47 views

Constructing query in Nominatim

I wonder how to construct the structured query URL for the OSM Nominatim? According to the documentation, one can use the free-form-query or the structured-query. This is the base url https://...
user avatar
  • 3,017
0 votes
0 answers
12 views

Is it possible to query using an attribute in Digital Earth Africa?

Am doing flood mapping in Digital Earth Africa(DEA), wondering if there is way to query using an attribute say water body to determine the built up areas that are prone to floods. Or is there another ...
user avatar
6 votes
1 answer
63 views

QGIS point layer: Select first point in each category

I have a point shapefile layer with several thousand points. Each record has a timestamp field and another field which defines a category to which that record belongs. There are about 200 different ...
user avatar
  • 373
2 votes
1 answer
28 views

Date operation in the Query Builder withPostGIS layer

I would like to filter a PostGIS layer by a datetime (QDateTime) field. I only want to show elements newer then 14 days. I tried the following expression in the Quary Builder: (day(now() - "...
user avatar
  • 23
2 votes
1 answer
56 views

Using LIKE with a Real field

Is it posible to use a wildcard in a field with real values? I am using QGIS. For example. I have a field with values from 0 to 10000, with increments of 10 metre, but would only like to display every ...
user avatar
1 vote
1 answer
37 views

MapInfo SQL Query with Metacharacters?

I have +8 million edge in MapInfo. I want to select character+digit but i cant. I tried querying as [a-z]+[0-9] but failed to use metacharacters in Mapinfo. "New York 1. Street" is true. &...
user avatar
  • 21
5 votes
2 answers
160 views

Matching colour of point to colour of polygon based on shared attribute using QGIS

I am setting a query on the symbology in QGIS. I have a layer of point locations (586 points which show the location that data has been collected) and I have a layer of polygon areas (576 polygons the ...
user avatar
0 votes
0 answers
39 views

SQL query on array data in ArcGIS attribute table

I have an attribute table where courses offered by different colleges are in an array, I am trying to Query using ArcGIS query builder so as to return colleges offering a specific course within the ...
user avatar
0 votes
1 answer
33 views

KML File - Python - Log Query

I want to know how many records are there in a KML file. Through what Python 2 code can I know this information?
user avatar
1 vote
0 answers
42 views

QGIS virtual layer SQL Query Arrays

I have a polygon layer (A) with a field containing the farmers that use that polygon (the UUID of each farmer): In each polygon feature can work from one to several farmers as it can be seen in the ...
user avatar
  • 53
4 votes
1 answer
62 views

Filter attribute information based on three different parameters and return ids using PyQGIS

I am having an attribute table information for line features. Each Line feature has LINK ID's which are supposed to be unique but in some places are repeating. Also I have a field "NEW" ...
user avatar
0 votes
0 answers
17 views

Modifying a REST directory to add a "FindNearest" feature

I'm currently building a tool to help people find information about their address in Paris but ran into a problem : Basically, I'm using an ArcGIS Rest service to find which building (polygon) an ...
user avatar
  • 1
1 vote
0 answers
42 views

Use spatial query to load WFS data into QGIS

I tried to load a WFS into my QGIS project but the number and complexity of the polygon features are to high to handle for QGIS so that it throws an error. So I tried to add a spatial query to the ...
user avatar
  • 11
1 vote
1 answer
36 views

Selecting max value from point table w. multiple repeated operators in query

How can I generate a query for the following issue? I have a table that has companies and values they have published to market. I am trying to display the highest value on a map, but unfortunately ...
user avatar
1 vote
1 answer
78 views

ST_LineLocatePoint does not exist

I'm trying to use some features recommended in another post here on the forum: I have this query to PostGIS: SELECT ST_LineLocatePoint ( ST_GeomFromText ( 'LINESTRING (174 425, 230 402, 246 369, 242 ...
user avatar
1 vote
1 answer
50 views

Invalid geometry point in ST_Distance query PostGIS

I have a problem that I can't get over .... I have a map on which there are several lines that represent some roads in the commune I click on the map and it gives me the position (latitude, longitude) ...
user avatar
3 votes
2 answers
100 views

Efficient combination of st_intersects and not st_touches

I'm attempting to an efficient way to find "overlapping" polygons. Specifically we have a bunch of postal code/city/neighborhood data where I specifically don't want the default behavior of ...
user avatar
2 votes
0 answers
31 views

MapServer / PostgreSQL don't display an ITEMQUERY

I try to search a string in MapServer with the method ITEMQUERY from a PostgreSQL table,. It look very simple but I receive the folow error: msPostGISLayerWhichShapes(): Query error. Error executing ...
user avatar
0 votes
0 answers
30 views

Intersection of 3d layers in PostGIS with SQL Queries

I am currently working on a project for Uni with PostGIS and SQL Queries. I am trying to calculate the intersection between two 3d layers. Based on online tutorials I came up with this query. SELECT ...
user avatar
0 votes
1 answer
54 views

Dynamically displaying polygon symbology by number of intersecting points as point layer updates using ArcGIS Pro

I have a set of polygons (municipal boundaries) and a point layer. I'd like to (eventually) create a WebApp to show the number of points inside each municipality, but that point layer is going to be ...
user avatar
  • 131
1 vote
0 answers
14 views

Merging queries to return ways/nodes that are within relations matching criteria using Overpass API

Motivation - I am currently processing a number of relations matching criteria and then doing an additional query to get all the ways/nodes within those relations. . Goal - I'm trying to simplify this ...
user avatar
  • 111
0 votes
0 answers
40 views

Excluding nodes in ways that are outside of intended area using Overpass API

The documentation for overpass states Nodes are found if they are properly inside or on the border of the area. Ways are found if at least one point (also points on the segment) is properly inside ...
user avatar
  • 111
0 votes
0 answers
37 views

Using Osmosis library to query data from a PBF file

I know that it's possible to read (crosby.binary.osmosis.OsmosisReader) and write (crosby.binary.osmosis.OsmosisSerializer) a PBF file using the Osmosis library. My question is if it's possible using ...
user avatar
1 vote
3 answers
179 views

Search for values in an attribute field based on a value relation in QGIS

I have a main postgresql table called "site" and another non geometrical local table called "values". I used the value relation widget on a text[] column named "choices" ...
user avatar
  • 129
5 votes
1 answer
114 views

Why highlighting duplicates does not work in QGIS?

I have used the formula from this query Identifying duplicate attributes in field using QGIS: count(1, "FieldWithDuplicates") > 1 but it doesn't work in my case, just highlights each ...
user avatar
  • 3,544
0 votes
1 answer
34 views

Max of count does not give me the result I need

I need to display the max of count for this query. I tried a nested way but I could not get it to return the centroid of that cell. Here flickr_edin table data consists of points and grid100m table ...
user avatar
  • 75
2 votes
1 answer
32 views

Query executed but returns blank screen

I have two tables, flickr_edin and routea flickr_edin contains columns id, date_taken, user and geom. routea consists of a single entry of a line string under the geom column. Use flickr table to show ...
user avatar
  • 75
2 votes
2 answers
95 views

Operation on mixed SRID geometries error

I have two tables flickr_edin and temmpat. temppat was created using: CREATE TABLE temppat (id serial, geom geometry); INSERT INTO temppat (geom) VALUES (ST_GeomFromText('POINT (326253.33 674110.63)'))...
user avatar
  • 75
0 votes
1 answer
35 views

Translate data right in ArcGIS Online?

I have a point feature layer in ArcGIS Online. I want to create a query on top of that FC that will translate the data: Calculate and concatenate fields Use coded value domain descriptions instead of ...
user avatar
  • 756
0 votes
0 answers
28 views

How to select areas based on "Northing"

I am a student working on an ArcGIS lab. I'm supposed to find campsites that meet this criteria; "campsite(s) that are also further north than 4,290,000 Northing" I know it's based on the &...
user avatar
  • 1
1 vote
1 answer
84 views

Extracting skatepark data as JSON file

I am new to QGIS but I need to create a JSON file with skatepark name and lat long. I have tried to use quickOSM plugin for QGIS with the tag leisure=pitch and sport=skateboard but it ends up giving ...
user avatar
  • 21
3 votes
1 answer
68 views

Querying for all solar farms in the UK using OSM and QGIS

I'm using the query function in QuickOSM plugin [out:json]; area["name"=United Kingdom"]->.searchArea; nwr(area.searchArea)["generator:source"="solar['generator:output:...
user avatar
  • 51
1 vote
0 answers
32 views

Missing some data from query in PostgreSQL

I am using this query to get elevation data from PostgreSQL: WITH points(geom) AS ( values (ST_SetSRID(ST_Point(980279.44, 6431129.89), 2154)), (ST_SetSRID(ST_Point(982573.24, 6429308....
user avatar
0 votes
1 answer
135 views

How to fetch all features, not just within the visible extent, using MapBox Studio hosted data?

I uploaded a GeoJSON Dataset to MapBox Studio, then converted it into a Tileset. I'm displaying this in a MapBox GL-JS map: map.addSource('regionsSource', { type: 'vector', url: 'mapbox://username....
user avatar
  • 20.5k
0 votes
0 answers
25 views

Removing rows limitation when making feature layer query using ArcGIS Python API

I have a fairly big spatiotemporal dataset located at a server, which gets additional 1000 rows every 10 seconds for like two moths already. I am concerned to download and process this data day by day,...
user avatar
4 votes
1 answer
125 views

Selecting all features from two polygon layers in one Virtual Layer in QGIS

I have two polygon layers that partially overlap: buidings and plots. Each layer has 126 features. I want to create a Virtual Layer that is simply an addition of the two layers, thus it should contain ...
user avatar
  • 40k
1 vote
2 answers
292 views

Make SQL spatial query for GeoPackage with PyQGIS in QGIS

I am trying to make SQL spatial query for GeoPackage with PyQGIS in my QGIS plugin. I get error message : "sqlite3.OperationalError: no such function: st_envelope" I can make the query ...
user avatar
  • 169
5 votes
1 answer
69 views

Query for adding new field that is the sum of months fields

I have a table where fields are a specific month of a year. And I just want to add a new field that is the sum of the months fields that are ticked. Practically speaking I need to know the duration of ...
user avatar
  • 61
0 votes
1 answer
36 views

Building selection query by looping through list [closed]

I would like to create a tool that selects census tracts based on input from a user. I have created an expression connecting values using "OR" but cannot figure out how to complete the ...
user avatar
  • 53
3 votes
1 answer
46 views

How to get the polygons from a shapefile that has been imported into PostGIS by a lat/lon query

I have imported the "water_polygons" from https://osmdata.openstreetmap.de/data/water-polygons.html and finally mangaged to setup PostGIS in a docker container. So the database is working: ...
user avatar
2 votes
1 answer
51 views

Queries for subset sub-setted data spatially in Virtual Layer

I need to fiddle together some small but smart queries in a Virtual Layer. I have a growing GPKG of field observations, and for easier analysis of the progress, I would like to create some queries in ...
user avatar
  • 3,064
0 votes
0 answers
48 views

Network analysis using QGIS

I have a water pipe network consisting of segments with attributes of pipe dimension, material of pipe and street location. I need to create another network with different segments grouped by these ...
user avatar
  • 405
2 votes
1 answer
58 views

Query for calculating length of lines inside polygon gives empty output [closed]

I am writing an SQL query to calculate the length of lines inside a polygon. SELECT r.*, st_length(st_intersection(r.geometry,b.geometry)) AS Length_Inside FROM Gen_Line as r, Buffered as b WHERE ...
user avatar
1 vote
0 answers
38 views

Importing a data table makes QGIS crash

I try to import a table with around 500.000 entities and it makes my computer load it endlessly then eventually crash. I do the same query with smaller tables and it usually works. How can I fix this?
user avatar
  • 61
0 votes
0 answers
63 views

Query point-intersection layer values with ArcGIS webmap (Python REST API)

I've created a webmap with ArcGIS. It has about 7 layers of information that are valuable to an app I am building. Is there any way to query intersecting layer values if I provide coordinates? For ...
user avatar
  • 101
0 votes
1 answer
177 views

ArcGIS JavaScript query task not returning feature

I am using query task to do a attribute query for features with a where clause. I have verified that the specific layer I am querying has the field LK_ID_NUM. My query task do not return an error, but ...
user avatar
  • 1
7 votes
2 answers
666 views

Multiple geometry types in one column not recognized

I often use PostGIS tables with a geometry column of type "Geometry" containing varying geometry types e.g. polygons and points. When opening the table in QGIS the Connections dialogue lists ...
user avatar

1
2 3 4 5
13