MongoDB地理查询动态坐标报错：Point must be an array or object 解决

问题场景 #

执行包含$match与$lookup的MongoDB聚合管道时，触发错误提示："Point must be an array or object"。问题出在$lookup的子管道中使用$geoIntersects，动态引用$mapboxAddress.geometry.coordinates作为Point坐标；但使用静态坐标时查询可正常运行，尝试$toDouble转换坐标值无效。

报错的聚合管道 #

[
  {
    "$match": {
      "mapboxAddress.complete": "Felix-Wankel-Straße 15, 74172 Neckarsulm, Germany"
    }
  },
  {
    "$lookup": {
      "from": "pg-boundaries-prod",
      "let": {
        "coordinates": "$mapboxAddress.geometry.coordinates"
      },
      "pipeline": [
        {
          "$match": {
            "geometry": {
              "$geoIntersects": {
                "$geometry": {
                  "type": "Point",
                  "coordinates": "$$coordinates"
                }
              }
            }
          }
        }
      ],
      "as": "boundariesData"
    }
  }
]

解决方法 #

改用$geoNear操作符替代$geoIntersects完成关联查询，最终可行的聚合管道如下：

[
  {
    "$geoNear": {
      "near": {
        "type": "Point",
        "coordinates": [9.225169, 49.193546]
      },
      "distanceField": "distance",
      "maxDistance": 1000 * 1000,
      "spherical": true
    }
  },
  {
    "$match": {
      "mapboxAddress.complete": "Felix-Wankel-Straße 15, 74172 Neckarsulm, Germany"
    }
  },
  {
    "$addFields": {
      "distanceInKm": {
        "$divide": ["$distance", 1000]
      },
      "modifiedMapboxAddress": {
        "$concat": ["$mapboxAddress.complete", ", Germany"]
      }
    }
  },
  {
    "$sort": {
      "distance": 1
    }
  },
  {
    "$lookup": {
      "from": "pg-boundaries-prod",
      "let": {
        "coordinates": "$mapboxAddress.geometry.coordinates"
      },
      "pipeline": [
        {
          "$geoNear": {
            "near": {
              "type": "Point",
              "coordinates": "$$coordinates"
            },
            "distanceField": "distance",
            "spherical": true
          }
        }
      ],
      "as": "boundariesData"
    }
  },
  {
    "$project": {
      "distanceInKm": 1,
      "boundariesData": {
        "$arrayElemAt": ["$boundariesData", 0]
      },
      "_id": 1,
      "mapboxAddress": 1,
      "corr": "$mapboxAddress.geometry.coordinates",
      "houseInfo": 1
    }
  },
  {
    "$limit": 1
  }
]

内容的提问来源于stack exchange，提问作者rushil patel