15.10 - ST_Boundary - Teradata Database

Teradata Database SQL Geospatial Types

Teradata Database
Programming Reference

Returns the boundary of the ST_Geometry value.

Returns an ST_Geometry value.

All ST_Geometry types.

Note: This method can be called on 3D geometries (those that include z coordinates). However, the z coordinate is ignored in method calculations. Consequently, any z coordinates returned by this method should be ignored. Teradata recommends using the Make_2D method to strip out the z coordinates of the return value.

The boundary of an ST_Geometry value is a set of ST_Geometry values of the next lower dimension.


IF the ST_Geometry represents …

THEN the boundary …

an ST_Point or ST_MulitPoint value

is the empty set.

a nonclosed ST_LineString or GeoSequence value

consists of the start and end ST_Point values.

a closed ST_LineString or GeoSequence value

is empty.

an ST_MultiLineString value

consists of ST_Point values that are in the boundaries of an odd number of its element ST_LineString values.

an ST_Polygon value

consists of its set of linear rings.

an ST_MultiPolygon value

consists of the set of linear rings of its ST_Polygon values.

an ST_GeomCollection where the interiors of the geometries in the collection are disjoint

consists of geometry values drawn from the boundaries of the element geometries, where the geometry values are in the boundaries of an odd number of element geometries.

   SELECT skey
   FROM sample_shapes
   WHERE shape.ST_Boundary().ST_IsEmpty() = 1;