Question

I have that class:

public class Post 
{
    public Oid Id { get; private set; }

    public IList<Comment> Comments { get; set; }
}

public class Comment
{
    public Guid Id { get;  set; }
    public DateTime TimePosted { get; set; }
}

how in linq select that posts whose comments has e.g TimePosted >= DateTime.Now ??

Answer 1

Given a collection of Post objects called “posts“, you’d do something like this:

var result = posts.Where(p => p.Comments.Any(c => c.TimePosted >= DateTime.Now));

Note that this is an example of Method syntax. For an example of Query syntax, see cybernate’s answer.

MSDN has a comparison of the two styles available here: LINQ Query Syntax versus Method Syntax.