Geometry Property Functions | ST_AsText(ST_Envelope(ST_GeomFromText(’LineString(1 1,2 2)’))) | +----------------------------------------------------------------+ | POLYGON((1 1,2 1,2 2,1 2,1 1)) | +----------------------------------------------------------------+ mysql>  SELECT ST_AsText(ST_Envelope(ST_GeomFromText(’LineString(1 1,1 2)’))); +----------------------------------------------------------------+ | ST_AsText(ST_Envelope(ST_GeomFromText(’LineString(1 1,1 2)’))) | +----------------------------------------------------------------+ | LINESTRING(1 1,1 2) | +----------------------------------------------------------------+ mysql>  SELECT ST_GeometryType(ST_GeomFromText(’POINT(1 1)’)); +------------------------------------------------+ | ST_GeometryType(ST_GeomFromText(’POINT(1 1)’)) | +------------------------------------------------+ | POINT | +------------------------------------------------+ 2304 ST_IsEmpty()  handles its arguments as described in the introduction to this section. The only valid empty geometry is represented in the form of an empty geometry collection value. MySQL does not support GIS  EMPTY  values such as  POINT EMPTY . This function is a placeholder that returns 1 for an empty geometry collection value or 0 otherwise. ST_GeometryType()  handles its arguments as described in the introduction to this section. Returns a binary string indicating the name of the geometry type of which the geometry instance  g  is a member. The name corresponds to one of the instantiable  Geometry  subclasses. ST_Envelope()  handles its arguments as described in the introduction to this section, with this exception: If the argument is a point or a vertical or horizontal line segment,  ST_Envelope()  returns the point or the line segment as its MBR rather than returning an invalid polygon: •If the geometry has an SRID value for a geographic spatial reference system (SRS), an ER_NOT_IMPLEMENTED_FOR_GEOGRAPHIC_SRS  error occurs. • ST_GeometryType( g ) • ST_IsEmpty( g )