嗨,我在 mongoDB 中有一个集合,我只想从中获取部分字段,我创建了一个类,用于向 Mongo 插入数据
类代码:
public class FrameDocument
{
public ObjectId _id { get; set; }
public Nullable<System.DateTime> FrameTimeStamp { get; set; }
public Nullable<int> ActivePick { get; set; }
public Nullable<int> TraderId { get; set; }
public Nullable<int> EventCodeId { get; set; }
public byte[] Frame { get; set; }
public int ServerUserId { get; set; }
public int SesionId { get; set; }
public string TraderName { get; set; }
public string ServerUserName { get; set; }
}
这是插入代码:
FrameDocument frameDoc = new FrameDocument();
frameDoc.Frame = imageBA;
frameDoc.EventCodeId = 1;
frameDoc.SesionId = 1;
frameDoc.FrameTimeStamp = DateTime.Now;
frameDoc.ServerUserId = (int)toMongoDt.Rows[0]["ServerUserId"];
frameDoc.TraderId = (int)toMongoDt.Rows[0]["TraderId"];
frameDoc.ActivePick = (int)toMongoDt.Rows[0]["ActivePick"];
frameDoc.TraderName = (string)toMongoDt.Rows[0]["TraderName"];
frameDoc.ServerUserName = (string)toMongoDt.Rows[0] ["ServerUserName"];
var mongoCon = "mongodb://127.0.0.1";
MongoClient client = new MongoClient(mongoCon);
var db = client.GetDatabase("Video");
var frameCollection = db.GetCollection<FrameDocument>("Frame");
frameCollection.InsertOne(frameDoc);
**现在我用这段代码得到了集合中的所有字段,但是我想把 Frame 字段排除在类之外,我试图在没有这个字段的情况下构建不同的类,但我不知道如何不这样做接收帧字段**
var collection = db.GetCollection<BsonDocument>("Frame");
var builder = Builders<BsonDocument>.Filter;
var filter = builder.Eq("SesionId", 1)
& builder.Eq("TraderId", 125)
& builder.Eq("ServerUserId", 1)
& builder.Lt("FrameTimeStamp", sing.eDate)
& builder.Gt("FrameTimeStamp", sing.sDate);
var result = collection.Find(filter).ToList();
有人可以帮忙吗?
最佳答案
请看这个:
_result = _collection.Find(o => o._id == _id)
.Project<FrameDocumentNoFrameField>
(Builders<FrameDocument>.Projection.Exclude(f => f.Frame)).ToList();
其中 FrameDocumentNoFrameField 是一个没有 Frame 字段的类
关于c# - 字段的 MongoDB C# 驱动程序投影,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38893114/