Select Distinct items

[Todd Forsberg]

I'm trying to use the new C# 2.0 "async" driver to retrieve distinct values only of a particular field from all documents in a collection.  

Can someone give a simple example of how to do this?  

I've searched all over the web and have not found any examples using the new driver.  There are plenty for the legacy driver.

[Craig Wilson]

Hi Todd,

What have you tried? There is a method called DistinctAsync on IMongoCollection.

var client = new MongoClient();

var db = client.GetDatabase("test");

var collection = db.GetCollection<BsonDocument>("people");

// get all the distinct values for the "firstName" field.

var distinctItems = collection.DistinctAsync("firstName", new BsonDocument());

Craig