ST_IsRing

Introduction: RETURN true if LINESTRING is ST_IsClosed and ST_IsSimple.

Format: ST_IsRing(geom: Geometry)

Since: v1.3.0

Example:

SELECT ST_IsRing(ST_GeomFromText("LINESTRING(0 0, 0 1, 1 1, 1 0, 0 0)"))

Output:

true