PostgreSQL npoints() Function

The PostgreSQL npoints() function counts the number of points on the specified path or polygon and returns it.

npoints() Syntax

This is the syntax of the PostgreSQL npoints() function:

npoints(geometric_type) -> integer

Parameters

geometric_type

Required. It can be a polygon polygon or a path path.

Return value

The PostgreSQL npoints() function returns the number of points on the path or polygon specified by the parameter.

npoints() Examples

The following statement shows how to use PostgreSQL npoints() function to count the number of points on the open path path '[(2,0),(0,0)]'.

SELECT npoints(path '[(2,0),(0,0)]');

 npoints
---------
       2

The following statement shows how to use PostgreSQL npoints() function to count the number of points on the close path path '((2,0),(0,0))'.

SELECT npoints(path '((2,0),(0,0))');

 npoints
--------
      2

The following statement shows how to use PostgreSQL npoints() function to count the number of points on polygon polygon '(0,0),(2,2),(4,0)'.

SELECT npoints(polygon '(0,0),(2,2),(4,0)');

 npoints
---------
       3