How to save a portion of a large document mongoDB C# driver

Question

Hi I have a document as follows

{
   "_id" : ObjectId("54c955492b7c8eb21818bd09"),
   "address" : {
      "street" : "2 Avenue",
      "zipcode" : "10075",
      "building" : "1480",
      "coord" : [ -73.9557413, 40.7720266 ],
   },
   "borough" : "Manhattan",
   "cuisine" : "Italian",
   "grades" : [
      {
         "date" : ISODate("2014-10-01T00:00:00Z"),
         "grade" : "A",
         "score" : 11
      },
      {
         "date" : ISODate("2014-01-16T00:00:00Z"),
         "grade" : "B",
         "score" : 17
      }
   ],
   "name" : "Vella",
   "restaurant_id" : "41704620"
}

lets assume that this document is so large and I want to Save or Update the cuisine value without saving the whole document, will it possible from the .net ORM wrapper?

Ex:- I only want to change the value "cuisine" without saving the whole document , please note that the real document is so big , will there be a performance issue ?

Answer 1

Use an update with $set to modify specific fields of an existing document.

In the shell:

db.mycoll.update({"_id": ObjectId("54c955492b7c8eb21818bd09")}, {$set: {cuisine: "Fast"}})

In C# with an untyped collection:

var filter = Builders<BsonDocument>.Filter.Eq("_id", new ObjectId("54c955492b7c8eb21818bd09"));
var update = Builders<BsonDocument>.Update.Set("cuisine", "Fast");
var result = await collection.UpdateOneAsync(filter, update);