{ "name": "num_geometries", "type": "function", "groups": ["GeometryGroup"], "description": "Returns the number of geometries in a geometry collection, or NULL if the input geometry is not a collection.", "arguments": [{ "arg": "geometry", "description": "geometry collection" }], "examples": [{ "expression": "num_geometries(geom_from_wkt('GEOMETRYCOLLECTION(POINT(0 1), POINT(0 0), POINT(1 0), POINT(1 1))'))", "returns": "4" }], "tags": ["collection", "multipart", "parts", "count"] }