Question

This is giving me a headache. I have this link query here that grabs an ID

Dim mclassID = From x In db.SchoolClasses Where x.VisitDateID = _visitdateID Select x.ClassID

And then later on I have this linq query

ViewData("Staff") = From t In db.Staffs Where t.ClassID = mclassID Select t

Any help would be much appreciated. I’ve tried quite a few things but to no avail. I’ve attempted casting, converting, Is operand, etc.

Answer 1

The problem is that myClassID is an anonymous IQueryable. You need to force it into another type (List is my favorite), and then pull it out of that type. So if you were to select it into a List(Of Integer) you could then extract the First() one since it would be the only. You could try something like this:

Dim myClassIDList As List(Of Integer) = New List(Of Integer)( _
    From x In db.SchoolClasses Where x.VisitDateID = _visitdateID Select x.ClassID)

Dim myClassID as Integer = myClassIDList.First()