Checks whether the spatial range of a geographic grid is contained within a geometry. Returns true if the grid falls inside the geometry, and false otherwise. This operator returns the spatial relationship between a grid and a geometry.
Syntax
The operator supports the following type combinations:
bool <@@(geometry geom3d, geomgrid gridcode)
bool <@@(geomgrid gridcode, geometry geom3d)
bool <@@(meshgeom geom3d, geomgrid gridcode)
bool <@@(geomgrid gridcode, meshgeom geom3d)
bool <@@(sfmesh geom3d, geomgrid gridcode)
bool <@@(geomgrid gridcode, sfmesh geom3d)
bool <@@(vomesh geom3d, geomgrid gridcode)
bool <@@(geomgrid gridcode, vomesh geom3d)
bool <@@(geomgrid gridcode1, geomgrid gridcode2)Parameters
| Parameter | Description |
|---|---|
gridcode / gridcode1 / gridcode2 | The geographic grid object. |
geom3d | The 3D geometry. |
The geometry must use the CGC2000 (China Geodetic Coordinate System 2000) spatial reference system. The spatial reference system identifier (SRID) of the geometry must be 4490.
Examples
Check whether a point geometry contains a geographic grid
The following example checks whether a 3D point at coordinates (116.315, 39.910, 1001.8 m altitude) contains the geographic grid GZ00262064446046072072.
SELECT 'srid=4490;POINT(116.31522216796875 39.910277777777778 1001.8)'::geometry,
<@@ ST_GridFromText('GZ00262064446046072072');Result:
st_3dwithin
-------------
tThe result t (true) confirms the grid falls within the specified geometry.
Check containment between two geographic grids
The following example checks whether the finer-grained grid GZ0026206435 is contained within the coarser grid GZ002620643.
SELECT ST_GridFromText('GZ0026206435') <@@ ST_GridFromText('GZ002620643');Result:
st_3dwithin
-------------
tThe result t (true) confirms that GZ0026206435 falls within the spatial range of GZ002620643.