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?

Getting the ids from the db after the operations will work, but it's less efficient since the ids are already in the driver. — i3arnon
ObjectIds don't increase monotonously, so your plan doesn't work. — CodesInChaos

i3arnon i3arnon · Accepted Answer · 2015-07-30T13:13:51

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);

MongoDb bulk operation get id

1 Answers