Question

I am having trouble to return an IEnumerable and IList, I cant do it!
I am using EF 4 with POCOs

Here’s the whole method:

//public IList<Genre> GetGenresByGame(int gameId)
public IEnumerable<Genre> GetGenresByGame(int gameId)
    {
        using(var ctx = new XContext())
        {
            var results =
                    from t0 in ctx.GameGenres
                    join t1 in ctx.GenreCultureDetails on t0.GenreId equals t1.GenreId
                    where t0.GameId == gameId && t1.CultureId == _cultureId
                    select new Genre
                    {
                        GenreId = t0.GenreId,
                        GenreName = t1.GenreName

                    };

            return results.ToList(); 
        }
    }

I have tried different ways that I have found on the net.. but can’t make it work!

Question 2:
I saw a screencast with Julie something, saying that “You should always return an ICollection” when using EF4.

Any thoughts about that ?

BR

EDIT:
When I load the page in Debug-mode i get these errors: The ObjectContext instance has been disposed and can no longer be used for operations that require a connection. OR The entity or complex type 'XModel.Genre' cannot be constructed in a LINQ to Entities query.

Answer 1

Genre must not be a L2EF type. Try this:

public IEnumerable<Genre> GetGenresByGame(int gameId)
{
    using(var ctx = new XContext())
    {
        var resultList =
                from t0 in ctx.GameGenres
                join t1 in ctx.GenreCultureDetails on t0.GenreId equals t1.GenreId
                where t0.GameId == gameId && t1.CultureId == _cultureId
                select new { t0.GenreId, t1.GenreName };
        var genres = resultList.AsEnumerable().Select(o => new Genre
                     {
                         GenreId = o.GenreId,
                         GenreName = o.GenreName
                     });
        return genres.ToList();
    }
}