Question

I have a view and entity

          var q = from stud in context.CollegePlans                                       
                 where stud .Meta.Active == true &&
                stud .CreatedBy_Id == user.Id
                select stud ;

        var k = from nv in context.vw_Year_Plans 
                 where ( nv.StudentId == q.Where( p => p.Section.StudentId))
                select nv;

studenId is Guid in both view and in entity..when i do the above it says cannot implictly convert system.Guid ? to bool ..how to overcome this ?

Answer 1

The expression evaluated by Where needs to evaluate to a boolean value.

where ( nv.StudentId = q.Where( p => p.Section.StudentId))

In this case, you have given it a Guid. That is where the error is coming from. I think you would have problems with that line even if the Where predicate was valid. From the looks of it, you want to want all of the StudentIds in context.vw_Year_Plans that are also in q.

A simple way to do that is to create an intermediate collection of the ids in q for comparison purposes.

var temp = q.Select(a => a.Section.StudentId);

Then see if each StudentId is also in context.vw_Year_Plans

var k = from nv in context.vw_Year_Plans
        where (temp.Contains(nv.StudentId)) 
        select nv;

There are better ways to solve this issue, but this should get you going.

EDIT

You mentioned using join in your comment. I haven’t tested either of these solutions but this should be what you need. If you are still having problems, update your question with more specific details on the issues you are facing.

var k = from nv in context.vw_Year_Plans
        join p in q on nv.StudentId equals p.Section.StudentId  
        select nv;