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Tag: postgis

How to split linestrings into their individual segments?

I am new to PostGIS. I have a set of (thousands) of Linestrings and associated multiple points along the line. I want to divide each line into a set of line segments consisting of only 2 points. I find a few answers, But none of the answers I want. for example My question: Answer Just dump the points of

Handle pg_error on generated columns

I have a table that consists of some PostGIS related data. These data are generated automatically on INSERT or UPDATE. Sometimes the data provided on the polygon column might not fit the generation function and cause an error. I wanted to handle this error and set a default value when it fail. — Last resort options — Creating postgres functions

Correct use of a LATERAL FROM

I am trying to use PostGIS to undertake a number of steps within an SQL statement to basically convert a raster to points, buffer, dissolve and then determine the overall boundary i.e. concave hull based on an attribute. The following is where I am at but get an error suggesting the use of a LATERAL FROM but I do not

How to insert value to a column as a result of geometry of another column in the same table

i have the database table posted below. the two columns geometryOfCellRepresentativeToTreatment and geometryOfCellRepresentativeToBuffer are of type geometry. and their value is equal the the geometry of the column fourCornersRepresentativeToTreatmentAsGeoJSON_ and fourCornersRepresentativeToBufferAsGeoJSON respectively. how can i insert the value into the latter columns as geometry of the former columns table: data_to_be_inserted: image Answer Just set the geojson strings to the geometry

how to iterate through geojson elements

i want to execute the code in this question but when i run the app i receive the following error: please let me know how to fix it. code: attempts: Answer From the database perspective the query works just fine, but the issue seems to be in the query building. Your query has a JSON document containing multiple “

PostGIS: Transform Linestring to LineString ZM

Problem: I have a series of geometries (LineString) saved in a Postgres database with additional information saved next to the geometry (a column for speed and time). I want to combine the three columns into a LineString ZM type so the geometry goes from a 2d to a 4d vector. id geometry speed time 1 LineString_A Int[] Float[] 2 LineString_B

PostgreSQL query update returns UPDATE 0

I am having trouble with a PostgreSQL query where my update condition contains more prerequisites. I attached 2 images to describe my problem. I want to update the highlighted row But the response is: Answer Your problem might be somewhere else (see this db<>fiddle) A few thoughts on your data: Reduce the level of precision of your coordinates. With 13