Question

I have a function that returns a JsonResult which should be a list of all object types that are associated to the provided guid. But I’m getting the error

LINQ to Entities does not recognize the method ‘System.Type GetType()’ method, and this method cannot be translated into a store expression.

Is this possible?

public JsonResult GetWebObjectTypesByWebObject(Guid id)
{
    JsonResult result = new JsonResult();
    var resultData = (from w in db.WebObjects
                      from r in w.RelatedWebObjects
                      where w.Id == id
                      select new { Type = r.GetType().BaseType.Name });
    result.Data = resultData;
    result.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
    return result;
}

Answer 1

Try this:

public JsonResult GetWebObjectTypesByWebObject(Guid id)
{
    JsonResult result = new JsonResult();
    var data = (from w in db.WebObjects
                      from r in w.RelatedWebObjects
                      where w.Id == id
                      select r).ToList();
    var resultData = data.Select(r => new { Type = r.GetType().BaseType.Name } );
    result.Data = resultData;
    result.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
    return result;
}

You loose the deferred execution but it seems irrelevant in this case.