与 linq 的连接查询不同

Question

I got 3 rows with same CommentingAuthor, how i do distinct to get 1 CommentingAuthor???

 IEnumerable<CommentingAuthor> CommentingAuthor =
                        from p in db.Posts
                        join c in db.Comments on p.WebSite equals c.CommentWebSite
                        select new CommentingAuthor
                        {
                            PostAuthorName = p.PostAuthor,
                            AuthorProfilePicture = c.CommentWebSite
                        };            

            return View(CommentingAuthor);

Answer 1

You can use Distinct . You may have to implement your own custom comparer.

var uniqueCommentingAuthors = CommentingAuthor.Distinct();

Using a customer comparer:

public class CommentingAuthorComparer : IEqualityComparer<CommentingAuthor>
{
    public bool Equals(CommentingAuthor author, CommentingAuthor author2)
    {
        return author.PostAuthorName.Equals(author2.PostAuthorName);
    }

    public int GetHashCode(CommentingAuthor author)
    {
        return author.PostAuthorName.GetHashCode();
    }
}

Then you can use it like:

   var comparer = new CommentingAuthorComparer();
   var uniqueAuthors = CommentingAuthor.Distinct(comparer);
   return View(uniqueAuthors);