[GIS] Delete duplicate polygon nodes with PostGIS

geometrypointpolygonpostgisqgis

I'm trying to delete duplicate nodes from a shapefile with QGIS, but after running the tool to delete it, nothing happens and shows the same errors.

I thought that maybe importing to postgis could be easier. What I want to do is:

  1. Extract points from polygon (this is already done)

  2. Delete the duplicate points ¿with st_equals?

  3. To finish, reshape the points to polygons without the duplicate points.

Anyone know if this methodology would be ok?
I can do the first and second steps, but don't know if number 3 is possible, or if there is a better alternative.

Any clue or suggestion?

Best Answer

If you are running PostGIS 2.0+, you can use the ST_RemoveRepeatedPoints function, so no need to go thru all that trouble of extracting and reconstituting

http://postgis.net/docs/manual-2.1/ST_RemoveRepeatedPoints.html

UPDATE yourpolygontable SET geom = ST_RemoveRepeatedPoints(geom);

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