ST_NPoints

ST_NPoints returns the number of nonempty points in an input geometry or geography.

Syntax

ST_NPoints(geo)

Arguments

geo

A value of data type GEOMETRY or GEOGRAPHY, or an expression that evaluates to a GEOMETRY or GEOGRAPHY type.

Return type

INTEGER

If geo is an empty point, then 0 is returned.

If geo is null, then null is returned.

Examples

The following SQL returns the number of points in a linestring.

SELECT ST_NPoints(ST_GeomFromText('LINESTRING(77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07)'));

st_npoints
-------------
 4               

The following SQL returns the number of points in a linestring in a geography.

SELECT ST_NPoints(ST_GeogFromText('LINESTRING(110 40, 2 3, -10 80, -7 9)'));

st_npoints
-------------
 4