LINQ: how to do "flat" collection instead of "nested"

Asked Oct 01 '19 at 13:40

Active Oct 01 '19 at 13:40

Viewed 14 times

I have a class:

public class CommentDto 
{
    public long Id { get; set; }
    //....
    public List<AttachmentDto> Attachments { get; set; }
}

I want to get AttachmentDto collection, which includes all Attachments from all Comments

I try to do it:

        var attachments = comments.Where(p => p.Attachments.Count > 0).Select(p => p.Attachments).ToList();

but it returns a collection with nested collections, but I want to have a one collection, which collects attachments from all comments

How to do it?

asked Oct 01 '19 at 13:40

Oleg Sh

1

Use `SelectMany(p => p.Attachments)`. Note that the `Where` is unnecessary in that case. – D Stanley Oct 01 '19 at 13:42
thank you very much! Please, do it as answer and I will vote it! – Oleg Sh Oct 01 '19 at 13:52
I already closed it as a duplicate question but wanted to give you a specific hint. But glad it worked. – D Stanley Oct 01 '19 at 14:33

0 Answers0