Class SpatialRelate
- Namespace
- YndigoBlue.Velocity.Functions
- Assembly
- YndigoBlue.Velocity.dll
Represents the ST_Relate spatial function that tests if two geometries satisfy a DE-9IM pattern.
public class SpatialRelate : Function, IElement, ICheckItem, IDefaultItem, IFilterItem- Inheritance
-
SpatialRelate
- Implements
Remarks
Warning
Spatial functions are not available in the Community Edition of Velocity. They require the Full Edition.
The ST_Relate function tests whether two spatial objects satisfy a specific spatial relationship defined by a Dimensionally Extended 9-Intersection Model (DE-9IM) pattern matrix. The mask parameter is a 9-character string representing the intersection patterns between interior, boundary, and exterior of both geometries. Values can be: T (true/non-empty), F (false/empty), * (don't care), 0 (point), 1 (line), 2 (area). This is the most flexible spatial predicate, allowing custom relationship definitions beyond the standard predicates. OGC-compliant.
Return Type: Boolean (true/false) when testing a pattern, or String (9-char matrix) when computing.
| DE-9IM Pattern | Equivalent Predicate |
|---|---|
| T*F**FFF* | ST_Contains |
| T*T***T** | ST_Crosses (for lines) |
| T*T***FF* | ST_Within |
| FF*FF**** | ST_Disjoint |
| FT******* | ST_Touches |
| T*T***T** | ST_Overlaps (for polygons) |
Constructors
- SpatialRelate(Geometry, Column, string)
Initializes a new instance of ST_Relate with a geometry literal, column, and DE-9IM mask.
- SpatialRelate(Column, Geometry, string)
Initializes a new instance of ST_Relate with a column, geometry literal, and DE-9IM mask.
- SpatialRelate(Column, Column, string)
Initializes a new instance of ST_Relate with two columns and a DE-9IM mask for cross-table spatial joins.
- SpatialRelate(Column, Geography, string)
Initializes a new instance of ST_Relate with a column, geography literal, and DE-9IM mask.
- SpatialRelate(Geography, Column, string)
Initializes a new instance of ST_Relate with a geography literal, column, and DE-9IM mask.