필드의 고유 값 가져오기

coll := client.Database("sample_mflix").Collection("movies")
filter := bson.D{{"directors", "Natalie Portman"}}
// Retrieves the distinct values of the "title" field in documents
// that match the filter
results, err := coll.Distinct(context.TODO(), "title", filter)
// Prints a message if any errors occur during the operation
if err != nil {
	panic(err)
}