How to update and upsert multiple documents in MongoDB using C# Drivers

Question

I am using MongoDB 2, and I want to update multiple documents and upsert a value like processed:true into the collection. But MongoDB c# api only allows us to either Update Multiple Records or Upsert a single record.

How to solve this problem using the C# api?

Answer 1

After Mongo 2.6 you can do Bulk Updates/Upserts. Example below does bulk update using c# driver.

MongoCollection<foo> collection = database.GetCollection<foo>(collectionName);
      var bulk = collection.InitializeUnorderedBulkOperation();
      foreach (FooDoc fooDoc in fooDocsList)
      {
        var update = new UpdateDocument { {fooDoc.ToBsonDocument() } };
        bulk.Find(Query.EQ("_id", fooDoc.Id)).Upsert().UpdateOne(update);
      }
      BulkWriteResult bwr =  bulk.Execute();

Answer 2

You cannot do it in one statement.

You have two options

1) loop over all the objects and do upserts

2) figure out which objects have to get updated and which have to be inserted then do a batch insert and a multi update