QGIS/resources/function_help/json/interior_ring_n

{
  "name": "interior_ring_n",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Returns a specific interior ring from a polygon geometry, or NULL if the geometry is not a polygon.",
  "arguments": [{
    "arg": "geometry",
    "description": "polygon geometry"
  }, {
    "arg": "index",
    "description": "index of interior to return, where 1 is the first interior ring"
  }],
  "examples": [{
    "expression": "geom_to_wkt(interior_ring_n(geom_from_wkt('POLYGON((-1 -1, 4 0, 4 2, 0 2, -1 -1),(-0.1 -0.1, 0.4 0, 0.4 0.2, 0 0.2, -0.1 -0.1),(-1 -1, 4 0, 4 2, 0 2, -1 -1))'),1))",
    "returns": "'LineString (-0.1 -0.1, 0.4 0, 0.4 0.2, 0 0.2, -0.1 -0.1))'"
  }],
  "tags": ["interior", "polygon", "hole", "ring"]
}