Class SpatialStartPoint

Namespace

YndigoBlue.Velocity.Functions

Assembly

YndigoBlue.Velocity.dll

Represents the ST_StartPoint spatial accessor function that returns the first point of a linestring geometry.

public class SpatialStartPoint : Function, IElement, ICheckItem, IDefaultItem, IFilterItem

Inheritance

object

Function

SpatialStartPoint

Implements

IElement

ICheckItem

IDefaultItem

IFilterItem

Remarks

Warning

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

The ST_StartPoint function returns a point geometry representing the first vertex of a linestring. For multi-linestrings or non-linestring geometries, behavior varies by database implementation (may return null or the start point of the first component). For Geometry types in planar coordinate systems, this is useful for analyzing line direction, connectivity analysis, network routing, or extracting terminal points from linear features. OGC-compliant.

Return Type: Point geometry.

Equivalent to: ST_PointN(line, 1)

Input	ST_StartPoint Result
Open LineString	First vertex
Closed LineString (ring)	First vertex (= last vertex)
MultiLineString	Start of first line only
Point, Polygon	NULL

Constructors

SpatialStartPoint(Geometry)

Initializes a new instance of ST_StartPoint with a linestring geometry literal.

SpatialStartPoint(Column)

Initializes a new instance of ST_StartPoint with a linestring geometry column.

SpatialStartPoint(Function)

Initializes a new instance of ST_StartPoint for a function result.

SpatialStartPoint(Geography)

Initializes a new instance of ST_StartPoint with a linestring geography literal.