Returns the level of a geographic grid. Accepts a single geomgrid, an array of geomgrid objects, or an h3grid.
Syntax
integer ST_Level(geomgrid gridcode);
integer[] ST_Level(geomgrid[] gridcode);
integer ST_Level(h3grid gridcode);
Parameters
| Parameter | Description |
|---|
gridcode | The geographic grid object. Accepts a geomgrid, a geomgrid array, or an h3grid. |
Return values
| Input type | Return type | Description |
|---|
geomgrid | integer | The level of the grid. |
geomgrid[] | integer[] | The level range across all grids in the array, returned as {min, max}. |
h3grid | integer | The level of the H3 grid cell. |
Examples
-- geomgrid (string input)
SELECT ST_Level(ST_GridFromText('GZ0026206440'));
st_level
----------
10
-- geomgrid array (3D geometry with holes)
SELECT ST_Level(ST_As3DGrid('srid=4490;GEOMETRYCOLLECTION Z (MULTIPOLYGON Z (((116 39 5000,116.12 39 5000,116.12 39.09 5000,116 39.09 5000,116 39 5000),
(116.024 39.018 5000,116.024 39.045 5000,116.06 39.045 5000,116.06 39.018 5000,116.024 39.018 5000))),
POINT Z (116 39 5000),MULTILINESTRING Z ((116 39 5000,116.024 39 5000),(116.012 39.009 5000,116.024 39.018 5000)),
POLYHEDRALSURFACE Z (((116 39 0,116 39 1000,116 39.009 0,116 39 0)),((116 39 0,116 39.009 0,116.012 39 0,116 39 0)),
((116 39 0,116.012 39 0,116 39 1000,116 39 0)),((116.012 39 0,116 39.009 0,116 39 1000,116.012 39 0))))'::geometry,
20,true));
st_level
----------
{19,20}
-- H3 grid (binary input)
SELECT ST_Level(ST_H3FromBinary('\x010100ffff9f6826a18408'));
st_level
----------
8