vb.net - How to write this LINQ/EF query? -

so have entity framework 5 model includes many-to-many relationship.

categoryvalues --< coursecategoryvalues >-- courses

i have linq query selects every course in database. modify select courses belong specific categoryvalue. attempt far has failed?

can me figure out?

this have tried:

using database sitedatacontext = new sitedatacontext     database.configuration.proxycreationenabled = false     database.courses.include("classes")     database.courses.include("coursecategoryvalues")     query = (from c in database.courses select c order c.name).where(                                                                         function(c) 0 < c.classes.where(function([class]) [class].status.tolower = "open").count                                                             ).include(function(r) r.classes).include(function(r) r.coursecategoryvalues)     ' here trying narrow down query results     if (pid.hasvalue) andalso (0 <> pid.value)         query.where(function(c) c.coursecategoryvalues.any(function(v) v.categoryvalue.categoryvalueid = pid))     end if      model.pagedata = query.tolist end using 

i think missing assignment of filter query variable. where returns new queryable, doesn't modify queryable apply where to. so, need:

query = query.where(...) 

the where expression looks correct me.