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ST_PointN

Returns the Nth point in a linestring.

Usage

geometry ST_PointN(geom: geometry, n: integer)

Arguments

  • geom (geometry): Input geometry
  • n (integer)

Description

Return the Nth point in a single linestring. Negative values are counted backwards from the end of the LineString such that -1 is the last point. Returns NULL if there is no linestring in the geometry.

Examples

SELECT ST_PointN(ST_GeomFromText('LINESTRING(0 0, 1 2, 2 4, 3 6)'), 2);

┌─────────────────────────────────────────────────────────────────────────────┐
│ st_pointn(st_geomfromtext(Utf8("LINESTRING(0 0, 1 2, 2 4, 3 6)")),Int64(2)) │
│                                   geometry                                  │
╞═════════════════════════════════════════════════════════════════════════════╡
│ POINT(1 2)                                                                  │
└─────────────────────────────────────────────────────────────────────────────┘