ST_Within function to query containment relationships between grids and geometries - PolarDB

Tests whether a geometry or grid lies entirely within another geometry or grid.

Syntax

boolean ST_Within(geomgrid grid, geometry geom);
boolean ST_Within(geometry geom, geomgrid grid);
boolean ST_Within(geomgrid grid1, geomgrid grid2);

Parameters

Parameter	Description
`grid`	The geomgrid value to test.
`geom`	The geometry value to test.

Description

ST_Within returns the spatial relationship between a grid and a geometry.

The geometry argument must use the China Geodetic Coordinate System 2000 (CGC2000) spatial reference system. Set its spatial reference system identifier (SRID) to 4490.

Examples

Example 1: Check whether a point lies within a grid

SELECT ST_Within(
  ST_GeomFromText('POINT(116.31522216796875 39.910277777777778)', 4490),
  ST_gridfromtext('G001331032213300013')
) AS geom_in_grid;

Output:

 geom_in_grid
--------------
 f

Example 2: Check whether a finer grid lies within a coarser grid

SELECT ST_Within(
  ST_gridfromtext('G001331032213300013'),
  ST_gridfromtext('G001331032213300')
) AS fine_in_coarse;

Output:

 fine_in_coarse
----------------
 t

G001331032213300013 is a finer-level subdivision of G001331032213300, so it is fully contained within the coarser grid.