ST_POINTN

Returns the Nth point in a single linestring. Negative values are counted backwards from the end of the line, so that -1 is the last point.

See also:

• ST_STARTPOINT
• ST_ENDPOINT
• ST_NPOINTS

Syntax

ST_POINTN(<linestring>, <n>)

Arguments

• <input>: The LINESTRING object
• <n>: INTEGER indicating which point to return

Returns

Returns a GEOGRAPHY point that is the Nth point in the linestring. Returns NULL if input is not of LINESTRING type, or index is invalid.

Example

SELECT ST_AsText(ST_POINTN('LINESTRING(0 0, 1 1, 2 2)'::GEOGRAPHY, 2));
-- POINT(1 1)