Mongo Csharp driver - upsert in nested array

Working with Data Drivers
,
1

I have an application with the following document structure:

{
  "_id" : ObjectId("123456789"),
  "DateStamp" : ISODate("2021-11-20T00:00:00.000Z"),
  "Codes" : [ 
  {
    "Code" : "1000",
    "Ident" : "ABC"
  }, 
  {
    "Code" : "1001",
    "Ident" : "DEF"
  },
  {
    "Code" : "1002",
    "Ident" : null
  }
  ]
}

For each day it exists such a document, with several codes.
The application needs sometime to upsert the codes for the actual day. The upsert rules are as following:

  • if the code is already existing for the day and the ident is not null → do nothing
  • if the code is already existing for the day and the ident is null → update the ident
  • if the code is not existing → insert new code+ident

Here is a sample application code:

public class MyDoc
{
public List<CodeInfo> Codes { get; set; }

[BsonElement("DateStamp")]
[BsonDateTimeOptions(Kind = DateTimeKind.Utc)]
public DateTime DateStamp { get; set; }
}

public class CodeInfo
{
public string Code { get; set; }
public string Ident { get; set; }
}      
   
Main()
{
...
  var actUtcDt = DateTime.UtcNow;
  var dateStr = actUtcDt.ToString("ddMMyyyy");
  var dayParsed = DateTime.ParseExact(dateStr, "ddMMyyyy", CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal);
  var dayParsedUtc = dayParsed.ToUniversalTime();

  var newCodes = new List<CodeInfo>
	       {
		  new CodeInfo { Code = "1000", Ident = "ABC2" },
		  new CodeInfo { Code = "1002", Ident = "EFGH" },
		  new CodeInfo { Code = "1003", Ident = "MNOP" }
	       };

  var myNewDoc = new MyDoc { DateStamp = dayParsedUtc, Codes = newCodes };

  UpsertMyDoc(myNewDoc);
  ...
}

void UpsertMyDoc(MyDoc myDoc)
{
  IMongoCollection<MyDoc> mongoCollection = ...;
  var filterMyDocBuilder = Builders<MyDoc>.Filter;
  var updateMyDocBuilder = Builders<MyDoc>.Update;

  var dtUtc = myDoc.DateStamp;

  var filterDate = filterMyDocBuilder.Eq(x => x.DateStamp, dtUtc);

  // only set on insert
  var updateDef = updateMyDocBuilder
      .SetOnInsert(p => p.DateStamp, dtUtc)
      .SetOnInsert(p => p.Codes, myDoc.Codes)
  ;
  var options = new UpdateOptions { IsUpsert = true };

  var updRes = await mongoCollection.UpdateOneAsync(filterDate, updateDef, options);
  var dayAvailable = updRes.IsAcknowledged && updRes.MatchedCount == 1 && updRes.UpsertedId == null;

  if (dayAvailable)
  {
....???
  }
}

It is expected that 1000 is ignored, 1002 updates the ident and 1003 is inserted. The “upserted” document should now look like this:

{
  "_id" : ObjectId("123456789"),
  "DateStamp" : ISODate("2021-11-20T00:00:00.000Z"),
  "Codes" : [ 
  {
    "Code" : "1000",
    "Ident" : "ABC"
  }, 
  {
    "Code" : "1001",
    "Ident" : "DEF"
  },
  {
    "Code" : "1002",
    "Ident" : "EFGH"
  },
  {
    "Code" : "1003",
    "Ident" : "MNOP"
  }
]
}

How can this be achieved with mongodb, in c# ?