Categories:: Geospatial functions

H3_POLYGON_TO_CELLS¶

Returns an array of INTEGER values of the IDs of H3 cells that have centroids contained by a Polygon (specified by a GEOGRAPHY object).

See also:: H3_POLYGON_TO_CELLS_STRINGS , H3_COVERAGE

语法

H3_POLYGON_TO_CELLS( <geography_polygon> , <target_resolution> )

实参

geography_polygon

表示多边形的 GEOGRAPHY 对象。

target_resolution

An INTEGER between 0 and 15 (inclusive) that specifies the H3 resolution (https://h3geo.org/docs/core-library/restable) that you want to use for the returned H3 cells.

指定其他任何 INTEGER 值都会导致错误。

返回 H3 单元格的 IDs 的 INTEGER 值数组，H3 单元格的质心包含在指定的输入多边形内。

使用说明

The function uses planar approximation, which treats points on the Earth’s surface as if they were connected by straight lines, rather than curved arcs. If you need a spherical approximation, use H3_COVERAGE instead.
如果单元格的质心包含在多边形内，则认为该单元格位于多边形内。
When you apply FLATTEN to the array returned by the function, cast each value explicitly to an integer.

示例

以下示例返回 H3 单元格 IDs 的 ARRAY，H3 单元格的质心包含在指定的多边形中。

SELECT H3_POLYGON_TO_CELLS(
  TO_GEOGRAPHY(
    'POLYGON((-122.481889 37.826683,-122.479487 37.808548,-122.474150 37.808904,-122.476510 37.826935,-122.481889 37.826683))'
  ),
  9) AS h3_cells_in_polygon;

+-----------------------+
| H3_CELLS_IN_POLYGON   |
%-----------------------%
| [                     |
|   617700171176476671, |
|   617700171168874495, |
|   617700171177525247, |
|   617700171167563775, |
|   617700171225497599, |
|   617700171188011007, |
|   617700171168350207, |
|   617700171168612351, |
|   617700171167825919  |
| ]                     |
+-----------------------+