$geoWithing in $lookup of MongoDB

Question

我正在寻找查询，以便在其他集合的查找中进行$geoWithin。

我实际拥有的是：

db.getCollection('polygons').aggregate([{ 
    $lookup: {
        from: "coll1",
        let: { geometry_poly: "$geometry" },
        pipeline: [
            { $match: { "location": { $geoWithin: { $geometry: "$$geometry_poly" } } } },
            { $project: { name: "$hashtag" } }
        ],
        as: "PolyAvg"
    }
}])

coll1：

{
    "_id" : ObjectId("5e90bf7b49ebb0e6b459a00f"),
    "hashtag" : "stayhome",
    "timestamp" : ISODate("2020-04-10T18:48:25.876Z"),
    "location" : {
        "type" : "Point",
        "coordinates" : [ 
            14.421425, 
            40.26084
        ]
    },
}

多边形：

{
    "_id" : ObjectId("5e95d56e49ebb0e6b45a34c4"),
    "type" : "Feature",
    "geometry" : {
        "type" : "Polygon",
        "coordinates" : [ 
            [ 
                [ ... , ... ]
            ]
        ]
    }
}

当我执行此命令时，它总是显示$$geometry_poly无效

Answer 1

目前，Geospatial Query Operators不接受expressions。