[postgis-users] How obtain the boundary between two polygon

[Marc Jansen]

Hi salas,

ST_Intersection should do the trick:

SELECT ST_AsText(
  ST_Intersection(
    'POLYGON((0 0, 2 0, 2 2, 0 2, 0 0))'::geometry,
    'POLYGON((2 1, 2 4, 4 4, 4 1, 2 1))'::geometry
  )
);
==> gives LINESTRING(2 1,2 2)


If you need a multi-geometry, use ST_Multi:

SELECT ST_AsText(
  ST_Multi(
    'LINESTRING(2 1,2 2)'::geometry
  )
);
==> gives MULTILINESTRING((2 1,2 2))


Regards,

Marc

fsalasGeocuba schrieb:
> Hi,
>
> I'ts possible to obtain the boundary between two polygon as polyline ?
>
> thanks ,
>
> salas
>
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