MongoDb bulk operation get id

Question

I want to perform bulk operation via MongoDb. How to get array of Ids that will be returned after it?

Can i perform single-operation insert faster without using bulk ? Can you advise me some other approach ? I'm using C# mongoDb driver 2.0 and MongoDb v. 3.0.2

update: I found the following solution - save maximum ObjectId of mongo collection,

db.col.find().sort({_id:-1}).limit(1).pretty()

and do the same after insert So we will get the range of inserted documents, does it make a sense?

Answer 1

You can insert items in bulk using the new driver with InsertManyAsync . If you want the Ids that the driver generated for these items you can simply get them out of the items themselves after they are inserted. For example:

Hamster[] hamsters = { new Hamster { Name = "Vaska" }, new Hamster { Name = "Petzka" } };
await collection.InsertManyAsync(hamsters);
var insertedIDs = hamsters.Select(_ => _.Id);