如何将MongoDb _id绑定到属性？

Question

I want to connect my ASP.NET Core web app to MongoDB, but got an issue.

I have a little model of Car

[BsonRepresentation(BsonType.ObjectId)]
public ObjectId ID { get; set; }
public string Company { get; set; }
public string Model { get; set; }
public string Color { get; set; }

[Range(1, 100)]
[DataType(DataType.Currency)]
public double Price { get; set; }

I also have a method which adds first data to my database: (in future I will add a method to the controller)

public async Task AddCar()
        {
            var mycar = new Car
            {
                Color = "red",
                Company = "my",
                Model = "x3",
                Price = 33
            };
            var collection = database.GetCollection<Car>("car");
            await collection.InsertOneAsync(mycar);
        }

Everything looks good, but when I run my program I get this data in DB

I want that the automatically generated _id property is matched with my ID property

What do I have to do to accomplish this?

Answer 1

You need to add the [BsonId] decorator before the [BsonRepresentation] one to tell MongoDB you are referring to it's autogenerated document ID. What happens now is MongoDB adding ID to the document while creating it and also another ID (yours) that's represented as the ObjectId but since you aren't really generating the value for your ObjectId , it's a bunch of zeroes.