All Questions
21
questions
1
vote
1
answer
56
views
Why do I need to use quotation marks ("") to call a table in PostGIS? I remember not to need it in other exercises [closed]
When I try to run the following code I get an error that disappear when I call the tables using quotation marks. I remember having run tables before without it.
select cine as INE from "...
- 153
3
votes
2
answers
116
views
Update fields in table in PostGIS database by joining attribute by field value from a layer
I have a table in my PostGIS database. Its geometric objects I loaded in to my QGIS project as layer where I can edit them. In this layer (layer A) there are features with null values in some fields. ...
- 65
0
votes
0
answers
20
views
How to add multiple shapefile into a single table in PostGIS? [duplicate]
How to add multiple same geometry shapefile (such as polygons) into a single table in PostGIS?
For example:
test_1 is a shapefile (polygon)
test_2 is a shapefile (polygon)
test_3 is a shapefile (...
- 55
4
votes
2
answers
632
views
PostGIS- slow spatial UPDATE queries on 50mil rows
PostgreSQL 11.8, AWS hosted RDS instance, SSD, 8GB RAM, 3.0 GHz Intel Scalable Processor. Plenty of storage space.
I'm finding running updates on a large table using spatial queries is taking a very ...
- 1,839
0
votes
0
answers
21
views
How to read postgres sql Table (No geometry) in PYQGIS? [duplicate]
In my database there is a table without geometry. how to read that from from pyqgis.
self.uri = QgsDataSourceUri()
self.uri.setConnection(self.Hostname, self.Portid, self.Dbname, self.Username, self....
- 1,205
1
vote
1
answer
509
views
Table to Distance Between in PostGIS
I am a new user in PostGIS.
I need to create a table with the ID_DIR of table A, ID_SQ of table B and have a new column called "Distance" that would be the distance between the ID_DIR and the ID_SQ in ...
1
vote
2
answers
119
views
Breaking lines in PostGIS?
I have a roads table and I want to break the lines in the intersections like the v.clean tool from GRASS (I'm talking about how the break tool in the parameters works).
How can I do the same process ...
- 31
1
vote
2
answers
485
views
Optimising a PostGIS table
I've been uploading a huge amount of contour information to a PostGIS / PostGres table. Uploaded using QGIS' db manager to a separate table a chunk at a time, and then using a quick bit of SQL to ...
- 904
2
votes
2
answers
12k
views
Limit the number of rows allowed in a table in PostgreSQL [closed]
I would like to set a maximum number of rows on a PostgreSQL table. I want users to be able to delete and recreate rows if need be; but there should never be more than x rows in my table. Is there a ...
- 586
2
votes
2
answers
2k
views
Selecting points within buffer using PostGIS?
I have approx 73,000 locations. For each location, I need to know which of the other locations is within a 1km radius from it. I would like this result to be in a table (so perhaps using a PostGIS ...
- 33
1
vote
1
answer
376
views
Convert PostGIS raster table into DTED2
I've the following table in PostGIS
-- Table: public.elevation_data
-- DROP TABLE public.elevation_data;
CREATE TABLE public.elevation_data
(
rid integer NOT NULL DEFAULT nextval('...
- 209
5
votes
1
answer
418
views
How to adapt a PostGIS query to modify the input table instead of creating a new table?
I use the following SQL query to create a table that contains dissovled polygons of an existing table:
-- Schema: public
-- Table: t_union
-- Input table: input_table
CREATE TABLE public.t_union AS ...
- 1,855
1
vote
0
answers
398
views
ST_Instersects and Join result to new table
I am having two tables, table1 and table2.
I want to know which parts of table2 intersect with table1. Having that information, I want to write the attributes from table2 into table1 (where they ...
- 3,398
2
votes
1
answer
526
views
How to set my ESPG to geography POINT in PostGIS?
I'm trying to create a table into my PostGIS 2.3
CREATE TABLE destinations (
id serial PRIMARY KEY,
sector integer REFERENCES sectors(id)...
- 288
2
votes
1
answer
997
views
Nearest Neighbour function
I'm trying to create a function which calculates the nearest neighbors under a certain length in a table s_1 an stores them in an output table.
This is what I've got so far:
CREATE OR REPLACE ...
- 316