ST_Boundary()

TL;DR

Use ST_Boundary() to return a geometry’s boundary.

Returns a geometry’s boundary.

Syntax

ST_Boundary(geom)

Arguments

Argument

Description

geom

A GEOMETRY or GEOMETRY32 value.

Return Value

Returns the same geometry precision type as geom.

Usage Notes

Examples

DROP DATABASE IF EXISTS geo_accessor_demo;
CREATE DATABASE geo_accessor_demo;
USE geo_accessor_demo;
SELECT ST_AsText(ST_Boundary(ST_GeomFromText('POLYGON((0 0,4 0,4 4,0 4,0 0)'))) AS boundary;
DROP DATABASE geo_accessor_demo;

See Also

ST_Envelope, ST_ExteriorRing