MongoDB C＃驱动程序：如何确保在数组内容上使用LINQ表达式的索引？

Question

How can I ensure an index using LINQ expressions on the contents of an array using the MongoDB C# driver?

I currently have a domain object that looks roughly like this:

public class Team
{
    public Team()
    {
        Members = new List<LazyReference>();
    }

    public MongoDB.Bson.ObjectId Id { get; set; }
    public string DisplayName { get; set; }
    public LazyReference Leader { get; set; }
    public List<LazyReference> Members { get; private set; }
}

public class LazyReference
{
    public MongoDB.Bson.ObjectId Id { get; set; }
}

On my collection, I have initialized a couple of indexes like this:

collection.EnsureIndex(IndexKeys<Team>.Ascending(t => t.DisplayName), IndexOptions.SetUnique(true));
collection.EnsureIndex(IndexKeys<Team>.Ascending(t => t.Leader.Id), IndexOptions.SetUnique(false));

How can I do the same to ensure a fast index of the Members when looking up by Members[n].Id, where n is any of the members? I am aware that I can create an index as follows, but since this does not use the LINQ expressions, it is not safe for future renames of properties.

collection.EnsureIndex(new IndexKeysBuilder().Ascending("Members._id"), IndexOptions.SetUnique(false));

I have also tried the following, but it only indexes the index specified:

collection.EnsureIndex(IndexKeys<Team>.Ascending(t => t.Members[0].Id), IndexOptions.SetUnique(false));

Answer 1

I ended up using the following:

await collection.Indexes.CreateOneAsync(Builders<Team>.IndexKeys.Ascending($"{nameof(Team.Members)}.{nameof(LazyReference.Id)}"), new CreateIndexOptions() { Unique = false });

this protects from property renaming but still not as elegant as Linq. The above code creates an index like { "Members._id" : 1 } .