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数据连接与集成PB函数表达式多边形中的第N链

注意：以下翻译的准确性尚未经过验证。这是使用 AIP ↗ 从原始英文文本进行的机器翻译。

多边形中的第N链

支持于: 批处理, 流处理

返回几何图形中单个多边形的第n个环。索引从1开始，索引为0表示超出范围。索引等于1返回外部环。索引大于1返回内部环。以下任一条件返回null：几何图形不是单个多边形，提供了要素集合或几何图形集合，索引超出范围，或至少一个参数为null。

表达式类别: 地理空间

声明的参数

  • N - 要检索的环的索引。索引从1开始，索引为0表示超出范围。索引大于1返回内部环。
    Expression<Byte | Integer | Long | Short>
  • Polygon - 要检索第n个环的多边形。
    Expression<Geometry>

输出类型: Geometry

示例

示例 1: 基本情况

参数值:

  • N: n
  • Polygon: polygon
polygonn输出
{"coordinates": [[[0.0, 0.0], [10.0, 0.0], [10.0, 10.0], [0.0, 10.0], [0.0, 0.0]]], "type": "Polygon"}1{"coordinates": [[0.0, 0.0], [10.0, 0.0], [10.0, 10.0], [0.0, 10.0], [0.0, 0.0]], "type": "LineString"}
{"coordinates": [[[0.0, 0.0], [10.0, 0.0], [10.0, 10.0], [0.0, 10.0], [0.0, 0.0]]], "type": "Polygon"}2null
{"coordinates":[[[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]],[[57.0,57.0],[55.0,52.0],[52.0,52.0],[50.0,57.0],[57.0,57.0]]],"type":"Polygon"}1{"coordinates": [[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]], "type": "LineString"}
{"coordinates":[[[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]],[[57.0,57.0],[55.0,52.0],[52.0,52.0],[50.0,57.0],[57.0,57.0]]],"type":"Polygon"}2{"coordinates": [[57.0,57.0],[55.0,52.0],[52.0,52.0],[50.0,57.0],[57.0,57.0]], "type": "LineString"}

示例 2: 空值情况

参数值:

  • N: n
  • Polygon: polygon
polygonn输出
{"coordinates": [[[[2.0, 2.0], [7.0, 2.0], [7.0, 7.0], [2.0, 7.0], [2.0, 2.0]]], [[[12.0, 12.0], [17.0, 12.0], [17.0, 17.0], [12.0, 17.0], [12.0, 12.0]]]], "type":"MultiPolygon"}1null
{"coordinates": [[[0.0, 0.0], [10.0, 0.0], [10.0, 10.0], [0.0, 10.0], [0.0, 0.0]]], "type": "Polygon"}nullnull
{"coordinates": [[[0.0, 0.0], [10.0, 0.0], [10.0, 10.0], [0.0, 10.0], [0.0, 0.0]]], "type": "Polygon"}0null
null1null
nullnullnull

示例 3: 边缘情况

参数值:

  • N: n
  • Polygon: polygon
polygonn输出
{"coordinates":[[[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]],[[57.0,57.0],[55.0,52....1{"coordinates": [[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]], "type": "LineString"}
{"coordinates":[[[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]],[[57.0,57.0],[55.0,52....2{"coordinates": [[57.0,57.0],[55.0,52.0],[52.0,52.0],[50.0,57.0],[57.0,57.0]], "type": "LineString"}
{"coordinates":[[[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]],[[57.0,57.0],[55.0,52....3{"coordinates": [[58.0,58.0],[58.0,59.0],[59.0,59.0],[59.0,58.0],[58.0,58.0]], "type": "LineString"}
{"coordinates":[[[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]],[[57.0,57.0],[55.0,52....4{"coordinates": [[52.0,58.5],[56.0,58.5],[54.0,57.5],[52.0,58.5]], "type": "LineString"}
{"coordinates":[[[60.0,60.0],[50.0,60.0],[50.0,50.0],[60.0,50.0],[60.0,60.0]],[[57.0,57.0],[55.0,52....5null