mongo C#驱动程序上的放松/项目出现问题

我试图从报告中获取所有点的数组，以便可以映射它们。要做到这一点，我需要放松/投射，但我正努力让我的头绕过它

结果的格式如下

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

如你所见，我得到了底部3项的空值

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();

将子文档数组转换为单个子文档，以便

.Unwind（x=>x.Locations）

之后的数据如下所示：

{ 
    "_id" : ObjectId("5e968bd5cc41498362cee2d2"), 
    "ReportTitle" : "aa", 
    "Locations" : { 
        "ItemId" : ObjectId("5e968bd5cc41498362cee2d3"), 
        "ItemName" : "Name", 
        "Name" : "N", 
        "Longitude" : 15, 
        "Latitude" : -24 
    } 
}

这意味着您必须重新考虑

intelreportlocationunbound

类定义。您可以使用与

IntelReport

中相同的类型，因为MongoDB只会将其从数组转换为嵌套对象：

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

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

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

然后，您可以修改聚合：

.Project(x => new LocationDto
        {
            ItemId = x.Id,
            ItemName = x.Name,
            Name = x.Location.Name,
            Latitude = x.Location.Latitude,
            Longitude = x.Location.Longitude
        })

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

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

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

.Project(x => new LocationDto
        {
            ItemId = x.Id,
            ItemName = x.Name,
            Name = x.Location.Name,
            Latitude = x.Location.Latitude,
            Longitude = x.Location.Longitude
        })