Class SpatialInteriorRingN
- Namespace
- YndigoBlue.Velocity.Functions
- Assembly
- YndigoBlue.Velocity.dll
Represents the ST_InteriorRingN spatial accessor function that returns the Nth interior ring (hole) of a polygon geometry.
public class SpatialInteriorRingN : Function, IElement, ICheckItem, IDefaultItem, IFilterItem- Inheritance
-
SpatialInteriorRingN
- Implements
Remarks
Warning
Spatial functions are not available in the Community Edition of Velocity. They require the Full Edition.
The ST_InteriorRingN function returns a linestring representing the Nth interior ring (0-based index) within a polygon geometry. Interior rings represent holes or voids in the polygon. The first interior ring is at index 0. For multi-polygons or non-polygon geometries, behavior varies by database implementation. For Geometry types in planar coordinate systems, this is useful for extracting polygon holes, analyzing complex polygon structure, or topology operations. OGC-compliant.
Return Type: LineString (closed ring representing the hole boundary).
| Function Call | Result |
|---|---|
| ST_InteriorRingN(polygon, 0) | First hole boundary |
| ST_InteriorRingN(polygon, 2) | Third hole boundary |
| ST_InteriorRingN(polygon_no_holes, 0) | NULL |
Constructors
- SpatialInteriorRingN(Geometry, int)
Initializes a new instance of ST_InteriorRingN with a polygon geometry literal and ring index.
- SpatialInteriorRingN(Column, int)
Initializes a new instance of ST_InteriorRingN with a polygon geometry column and ring index.
- SpatialInteriorRingN(Function, int)
Initializes a new instance of ST_InteriorRingN for a function result.
- SpatialInteriorRingN(Geography, int)
Initializes a new instance of ST_InteriorRingN with a polygon geography literal and ring index.