Table of Contents

Class SpatialNumInteriorRing

Namespace
YndigoBlue.Velocity.Functions
Assembly
YndigoBlue.Velocity.dll

Represents the ST_NumInteriorRing spatial property function that returns the number of interior rings (holes) in a polygon.

public class SpatialNumInteriorRing : Function, IElement, ICheckItem, IDefaultItem, IFilterItem
Inheritance
SpatialNumInteriorRing
Implements

Remarks

Warning

Spatial functions are not available in the Community Edition of Velocity. They require the Full Edition.

The ST_NumInteriorRing function returns the count of interior rings (holes) within a polygon geometry. The exterior ring is not counted. For multi-polygons or non-polygon geometries, behavior varies by database implementation. Interior rings represent holes or voids within the polygon boundary. For Geometry types in planar coordinate systems, this is useful for analyzing polygon complexity, identifying features with holes, or validating polygon structure. OGC-compliant.

SpatialNumInteriorRing diagram showing hole counts

Return Type: Integer (count of holes).

PolygonST_NumInteriorRing Result
Simple polygon (no holes)0
Polygon with 1 hole1
Polygon with 6 holes6
Point, LineStringNULL or 0

Constructors

SpatialNumInteriorRing(Geometry)

Initializes a new instance of ST_NumInteriorRing with a polygon geometry literal.

SpatialNumInteriorRing(Column)

Initializes a new instance of ST_NumInteriorRing with a polygon geometry column.

SpatialNumInteriorRing(Function)

Initializes a new instance of ST_NumInteriorRing for a function result.

SpatialNumInteriorRing(Geography)

Initializes a new instance of ST_NumInteriorRing with a polygon geography literal.