<@-AnalyticDB(AnalyticDB)-阿里云帮助中心

Returns true if a grid is contained within a geometry, or if one grid is contained within another grid.

Syntax

boolean <@(geomgrid grid, geometry geom);
boolean <@(geometry geom, geomgrid grid);
boolean <@(geomgrid grid1, geomgrid grid2);

Parameters

Parameter	Description
`grid`	The grid to test for containment.
`geom`	The geometry to test against.

Description

The <@ operator checks whether a grid or geometry is spatially contained within another grid or geometry.

The geometry argument must use the CGC2000 spatial reference system — the Chinese national coordinate standard. Its spatial reference system identifier (SRID) must be 4490.

Examples

Example 1: Check whether a geometry point is contained in a grid. The point falls outside the grid, so the result is f.

SELECT ST_GeomFromText('POINT(116.31522216796875 39.910277777777778)', 4490) <@
    ST_GridFromText('G001331032213300013') AS is_contained;

 is_contained
--------------
 f

Example 2: Check whether a smaller grid is contained in a larger grid. The result is t.

SELECT ST_GridFromText('G001331032213300013') <@
    ST_GridFromText('G001331032213300') AS is_contained;

 is_contained
--------------
 t