不确定我在做什么错得到错误：无法将类型'System.Linq.IQueryable'1强制转换为类型'System.Linq.IQueryable'1'

Question

i have this query:

var model2 = (from p in context.ViewChatPeoples
                           where ((IQueryable<int>)(from q in context.ConversationPeoples
                           where !q.Deleted && q.PersonId == info.LoginID
                           select new { q.ConversationId })).Contains(p.ConversationId)
                      select p.ConversationId).Distinct().ToList();

in LINQ / C#, however it seems to produce the following error:

Unable to cast the type 'System.Linq.IQueryable`1' to type 'System.Linq.IQueryable`1'. LINQ to Entities only supports casting Entity Data Model primitive types.

makes zero sense, i just want to run an WHERE IN, but seem to have hit this hurdle that makes no sense what so ever !!!

thanks

and as an update here is the final working code using the given solution:

var model2 = (from p in context.ViewChatPeoples
                           where ((from q in context.ConversationPeoples
                           where !q.Deleted && q.PersonId == info.LoginID
                           select q.ConversationId)).Contains(p.ConversationId)
                      select p.ConversationId).Distinct().ToList();

Answer 1

select new { q.ConversationId } creates an anonymously typed object with a property ConversationId. The code creates an IQueryable<[anonymous type]> instead of an IQueryable< int>.

simply select q.ConversationId to get an IQueryable< int>.

Answer 2

I think it's because the return type of your subquery isn't IQueryable<int> but IQueryable<anonymousType> . Changing the select from select new { q.ConversationId } to select q.ConversationID should resolve (untested).