mongo C＃驱动程序上的展开/项目故障

Question

我正在尝试从报告中获取所有点的数组，以便可以对其进行映射。为此，我需要放松/投射，但我一直在努力解决这个问题。

结果格式如下。

"totalPoints": 200,
    "points": [
        {
            "itemId": "5e9592edb4959a52b8493f6d",
            "itemName": "Numquam hic minus repellat sequi.",
            "name": null,
            "longitude": null,
            "latitude": null
        },
...

正如您所看到的，我的前三项都为空。

这是我正在使用的查询

            var points = await _reportDocs.Aggregate()
                .Match(filter.GenerateFilter())
                .Unwind<IntelReport, IntelReportLocationUnwound>(x => x.Locations)
                .Project(x => new LocationDto
                {
                    ItemId = x.Id,
                    ItemName = x.Name,
                    Name = x.Location.Name,
                    Latitude = x.Location.Point.Coordinates[1],
                    Longitude = x.Location.Point.Coordinates[0]
                })
                .ToListAsync();

这里是原始报告类（但是我​​已经删除了一些不需要的东西）

 public class IntelReport
    {
        [BsonId]
        [BsonRepresentation(BsonType.ObjectId)]
        public string Id { get; set; }
        public string ReportTitle { get; set; }
        public ICollection<Location> Locations { get; set; }

    }

以及我认为需要放松的课程...

 public class LocationDto
    {
        [BsonRepresentation(BsonType.ObjectId)]
        public string ItemId { get; set; }
        public string ItemName { get; set; }
        public string Name { get; set; }
        public double? Longitude { get; set; }
        public double? Latitude { get; set; }
    }

    [BsonIgnoreExtraElements]
    public class IntelReportLocationUnwound
    {
        [BsonId]
        [BsonRepresentation(BsonType.ObjectId)]
        public string Id { get; set; }

        [BsonElement("ReportTitle")]
        [BsonIgnoreIfDefault]
        public string Name { get; set; }

        [BsonElement("locations")]
        [BsonIgnoreIfDefault]
        public LocationForAgg Location { get; set; }
    }

    public class LocationForAgg
    {
        [BsonElement("name")]
        [BsonIgnoreIfDefault]
        public string Name { get; set; }

        [BsonElement("point")]
        [BsonIgnoreIfDefault]
        public PointForAgg Point { get; set; }
    }

    public class PointForAgg
    {
        [BsonElement("coordinates")]
        [BsonIgnoreIfDefault]
        public double[] Coordinates { get; set; }
    }

Answer 1

[$unwind将一个子文档数组转换为一个子文档，因此，.Unwind<IntelReport, IntelReportLocationUnwound>(x => x.Locations)之后的数据将如下所示：