ST_CoverageEdges
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Name

ST_CoverageEdges — Computes the unique edges of a polygonal coverage.

Synopsis

geometry ST_CoverageEdges(geometry geom, integer edgetype = 0);

geometry ST_CoverageEdges(geometry[] geoms, integer edgetype = 0);

Descripción

Returns a MultiLineString representing the unique edges of a polygonal coverage. A polygonal coverage is a set of non-overlapping polygons where adjacent polygons have matching vertices along shared edges.

The edgetype parameter can be used to select which edges are returned:

  • 0 (ALL) - all unique edges (default)

  • 1 (EXTERIOR) - only exterior edges (non-shared)

  • 2 (INTERIOR) - only interior edges (shared)

Availability: 3.7.0

Requires GEOS >= 3.15.0

Ejemplos

-- Get all unique edges of a coverage
SELECT ST_AsText(ST_CoverageEdges(ST_GeomFromText('GEOMETRYCOLLECTION(POLYGON((0 0, 10 0, 10 10, 0 10, 0 0)), POLYGON((10 0, 20 0, 20 10, 10 10, 10 0)))')));
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MULTILINESTRING((0 0, 10 0), (10 0, 20 0), (20 0, 20 10), (20 10, 10 10), (10 10, 0 10), (0 10, 0 0), (10 0, 10 10))

-- Get only interior (shared) edges
SELECT ST_AsText(ST_CoverageEdges(ST_GeomFromText('GEOMETRYCOLLECTION(POLYGON((0 0, 10 0, 10 10, 0 10, 0 0)), POLYGON((10 0, 20 0, 20 10, 10 10, 10 0)))'), 2));
--------------------------------------
MULTILINESTRING((10 0, 10 10))