UpdateManyAsync()
is the function in .net 4.5 and later versions for updating one or more number
of records in MongoDB. It will also updates one record if your selection matches only one
record
Example:
var updmanyresult = await
collection.UpdateManyAsync(
Builders<BsonDocument>.Filter.Gt("MasterID", 100),
Builders<BsonDocument>.Update.Inc("MasterID", 10));