What do ST_DISTANCE, ST_CONTAINS, ST_INTERSECTS, ST_ASGEOJSON do?
In Snowflake, the functions ST_DISTANCE, ST_CONTAINS, ST_INTERSECTS, and ST_ASGEOJSON are part of the geospatial functions and are used to perform operations on spatial data.
1. ST_DISTANCE:
- ST_DISTANCE(geometry1, geometry2): Calculates the distance between two spatial objects, such as points, lines, or polygons.
- Example: ST_DISTANCE(point1, point2) calculates the distance between two points.
2. ST_CONTAINS:
- ST_CONTAINS(geometry1, geometry2): Determines if one spatial object is completely contained within another spatial object.
- Example: ST_CONTAINS(polygon, point) checks if a point is within a polygon.
3. ST_INTERSECTS:
- ST_INTERSECTS(geometry1, geometry2): Determines if two spatial objects intersect or have any common points.
- Example: ST_INTERSECTS(line1, line2) checks if two lines intersect.
4. ST_ASGEOJSON:
- ST_ASGEOJSON(geometry): Converts a spatial object to its equivalent representation in GeoJSON format.
- Example: ST_ASGEOJSON(polygon) converts a polygon to its GeoJSON representation.
These geospatial functions are useful for working with spatial data and performing various spatial operations and analyses. They enable distance calculations, containment checks, intersection detections, and conversion to the widely used GeoJSON format for interoperability with other geospatial tools and systems.
It's worth noting that the specific behavior and usage of these functions may vary depending on the geometry type (point, line, polygon) and the coordinate reference system used. The Snowflake documentation provides more details on the syntax and usage of these functions, along with examples and considerations for working with geospatial data.