You can get some inspiration for updating a document in the quick-tour documentation provided on the MongoDB site: http://mongodb.github.io/mongo-csharp-driver/2.5/getting_started/quick_tour/
Just look at the Updating Document section.
But to save a click you can use the following code as an inspiration:
// Setup the connection to the database
var client = new MongoClient("mongodb://localhost");
var database = client.GetDatabase("Library");
var collection = database.GetCollection<BsonDocument>("books");
// Create a filter to find the book with ID 1
var filter = Builders<BsonDocument>.Filter.Eq("ID", 1);
var update = Builders<BsonDocument>.Update.Set("Book_Author", "New Book owner");
collection.UpdateOne(filter, update);
I hope this helps.
solved In sqlite I would do, But how in mongodb c#