LINQ Query returning IQueryable, need it to be a single result

Question

I currently have a LINQ query written in one my controllers that I want to return a single blog post (based off a model) with corresponding comments and topics.

This is what I currently have as my query which I used to return a list of all my blog posts for the home page. I added "where p.id == id (which is the parameter taken in by the ActionResult to fetch the correct post.

var post = from p in db.Set<BlogPost>()
                   where p.id == id
                   select new PostViewModel
                              {
                                  Id = p.id,
                                  Title = p.Title,
                                  DateCreated = p.DateCreated,
                                  Content = p.Content,
                                  Topics = p.Topics,
                                  Comments = p.Comments,
                                  CommentCount = p.Comments.Count
                              };

return View(post);

The return currently is sending an IQueryable when I just want it to be a single post. Currently I have a foreach in my razor view which is useless and wrong but it works. How can I change this to do what I want?

Answer 1

replace your LINQ with this

var post = (from p in db.Set<BlogPost>()
               where p.id == id
               select new PostViewModel
                          {
                              Id = p.id,
                              Title = p.Title,
                              DateCreated = p.DateCreated,
                              Content = p.Content,
                              Topics = p.Topics,
                              Comments = p.Comments,
                              CommentCount = p.Comments.Count
                          }).FirstOrDefault();

Answer 2

Just do post.First() that should do the trick. Really any function that produces a concrete value will work. First, FirstOrDefault, Single, SingleOrDefault, ToList, or ToArray

I have included the links to each method so you can see what works for you. It sounds like you will want a First or Single variation, depending on if you want errors if more than one post is pulled

Answer 3

You can do:

return View(post.SingleOrDefault());

Or if you want to have an exception in the case list is empty:

return View(post.Single());

Answer 4

It sound like you want to use First or Single:

return View(post.Single());

The difference between them is that Single will throw an exception if more than one matching row is found.

Answer 5

Just add First() or Single() (which one is right for you depends on context) to your query:

return View(post.First());