LinqPad Query to Visual Studio - how to use a nested query to populate a viewmodel - asp.net

Question

This is a follow up to an earlier question.
I want to populate a ViewModel, which has 3 properties, and one list of Occ class (which also has 3 properties.
public class RatesViewModel
{
public string TypeName { get; set; }
public long TypeID { get; set; }
public int TypeCount { get; set; }
public virtual IQueryable<Occ> Occs { get; set; }
}
public class Occ
{
public string occ { get; set; }
public decimal ratetocharge { get; set; }
public int numOfOcc { get; set; }
public virtual RatesViewModel RatesViewModel { get; set; }
}
When I run the following Linq query in LinqPad:
var rooms = tblRoom
.GroupBy(p => p.tblType)
.Select(g => new
{
TypeName = g.Key.type_name,
TypeID = g.Key.type_id,
TypeCount = g.Count(),
Occs = rates.Where(rt => rt.type_id == g.Key.type_id &&
(
(rt.type_id == g.Key.type_id)
))
.GroupBy(rt => rt.occ)
.Select(proj => new
{
occ = proj.Key,
ratetocharge = proj.Sum(s => s.rate),
numOfOcc = proj.Count()
})
});
rooms.Dump();
...as before, it correctly returns the data model I'm looking for:
...and when I click on Occs it drills down into the Occs class:
The complete view in LinqPad is:
My query in Visual Studio is:
var rooms = dbr.Rooms
.GroupBy(p => p.RoomTypes).Select(g => new RatesViewModel
{
TypeName = g.Key.type_name,
TypeID = g.Key.type_id,
TypeCount = g.Count()
,
Occs = db.Rates.Where(rt => rt.type_id == g.Key.type_id &&
(
(rt.type_id == g.Key.type_id)
))
.GroupBy(rt => rt.occ)
.Select(proj => new Occ
{
occ = proj.Key,
ratetocharge = proj.Sum(s => s.rate),
numOfOcc = proj.Count()
})
})
.ToList();
However when running this, I get an error:
The specified LINQ expression contains references to queries that are associated with different contexts.
I think I understand the error - but I'm not sure how to separate the query into 2 separate queries, and then join those query results together again to get my original results set.
My model classes are:
public class Rates
{
public int id { get; set; }
public long type_id { get; set; }
public DateTime ratedate { get; set; }
public decimal rate { get; set; }
public string occ { get; set; }
public List<RoomType> Type { get; set; }
}
public class Rental
{
[Key]
public long rental_id { get; set; }
public long room_id { get; set; }
public DateTime check_in { get; set; }
public DateTime check_out { get; set; }
public virtual Room Room { get; set; }
}
public class Room
{
[Key]
public long room_id { get; set; }
public long type_id { get; set; }
public virtual RoomType RoomTypes { get; set; }
public virtual ICollection<Rental> Rentals { get; set; }
}
public class RoomType
{
[Key]
public long type_id { get; set; }
public string type_name { get; set; }
public IQueryable<Rates> Rates { get; set; }
public virtual ICollection<Room> Room { get; set; }
}
Can anyone help either review my query or models, so it works with one query, or show me how to separate the query into two, and then combine the result sets?
Thank you,
Mark

Answer 1

apitest.Models.RoomContext' does not contain a definition for 'Rates'...
(your comment on hydr's answer)
Well, there you go: not only two different context instances but two different context classes. I suspect your linqpad query was directly against the database connection, which means it used one linq-to-sql DataContext (created on the fly).
You need to use one context class (and one instance of it) in your query. And connect to it in Linqpad to make sure you test the same query provider as Visual Studio.

Answer 2

dbr and db seem to be two different instances of the same context. But in one query you should only use one context. So I would suggest the following:
Occs = dbr.Rates.Where(rt => rt.type_id == g.Key.type_id && ....
If this doesn't help can you quote the lines where you initialize the contexts?