Linq To Entities 'Only primitive types or enumeration types are supported' Error

Question

I am using LinqPad to test my query. This query works when the LInqPad connection is to my database (LInq to SQL) but it does not work when I change the connection to use my

Answer 1

basically it means you are using some complex datatype inside the query for comparison. in your case i suspect from p in this.Plans where p.PlanID == pd.PlanID is the culprit.

And it depends on DataProvider. It might work for Sql Data Provider, but not for SqlCE data Provider and so on.

what you should do is to convert your this.Plans collection into a primitive type collection containing only the Ids i.e.

var integers = PlanDetails.Plans.Select(s=>s.Id).ToList();

and then use this list inside.

var q = from pd in PlanDetails
        select new {
            pd.PlanDetailID,
            ThePlanName = (from p in integers
                    where p == pd.PlanID
                    select pd.PlanName)
        };