Cannot implicitly convert type 'System.Linq.IQueryable?

Question

here is my code which is giving me above error

    public ActionResult  Edit(int id = 0)
    {
        KBS_Virtual_TrainingEntities db = new KBS_Virtual_TrainingEntities();
        UsersContext ctx = new UsersContext();
        UserProfile model = ctx.UserProfiles.Find(id);

        List<CourseSubscription> user_Course_subscriptions = new List<CourseSubscription>();



        foreach (UserSubscription sub in db.UserSubscriptions)
        {
            if (sub.ID == id)
            {
                user_Course_subscriptions.Add(sub.CourseSubscription);
            }
        }
        List<CourseSubscription> not_subscribe = db.CourseSubscriptions.Except(user_Course_subscriptions);

        var coursesList = from courses in not_subscribe
                          select new SelectListItem
                          {
                              Text = courses.Course.Name,
                              Value = courses.Course.ID
                              .ToString()
                          };
        var CoursesTYPE = from CourseTypes in db.CourseTypes.ToList()
                          select new SelectListItem
                          {
                              Text = CourseTypes.Name,
                              Value = CourseTypes.ID
                              .ToString()
                          };

        ViewBag.CourseID = coursesList;
        ViewBag.type = CoursesTYPE;
        return View(model);

    }

I am trying to find Course Subscription that are not subscribe by the current user by using the above code but its not working?

telling at which line of code the exception was thrown exactly may help — har07, Mar 10 '14 at 05:58
List not_subscribe = db.CourseSubscriptions.Except(user_Course_subscriptions); — Zahid Nisar, Mar 10 '14 at 05:59
posting complete exact error message also helpful, like this one (possible duplicate btw) : [Cannot implicitly convert type 'System.Linq.IQueryable' to 'System.Collections.Generic.IList'](http://stackoverflow.com/questions/3402822/cannot-implicitly-convert-type-system-linq-iqueryable-to-system-collections-g) — har07, Mar 10 '14 at 06:04
Error 327 Cannot implicitly convert type 'System.Linq.IQueryable' to 'System.Collections.Generic.List'. An explicit conversion exists (are you missing a cast?) this error I am getting — Zahid Nisar, Mar 10 '14 at 06:08
yep, check answer given in the link above. It is almost identical to your problem (only difference is `List` here vs `IList` in the other post). And of course check answer from @McAden — har07, Mar 10 '14 at 06:12

score 2 · Accepted Answer · answered Mar 10 '14 at 06:01

You're missing ToList on the results from your Except function. Do a ToList like so:

List<CourseSubscription> not_subscribe = db.CourseSubscriptions.Except(user_Course_subscriptions).ToList();

Or since in your code you're not doing anything that needs a list, simply var it or assign the correct type to it such as IQueryable<CourseSubscription> to it.

var not_subscribe = db.CourseSubscriptions.Except(user_Course_subscriptions);

Cannot implicitly convert type 'System.Linq.IQueryable?

1 Answers1