Question

Here’s a LINQ statement that I am trying to execute

var usersQuery =
from user in Model.Users
select user.Plates;

var platesQuery =
from plate in usersQuery
group plate by plate.Time into grouping
select grouping;

I get the following error

System.Collections.Generic.List<AllYourPlates.Domain.Entities.Plate>' does not contain a definition for 'Time' and no extension method 'Time' accepting a first argument of type 'System.Collections.Generic.List<AllYourPlates.Domain.Entities.Plate>' could be found (are you missing a using directive or an assembly reference?

I can’t figure out what the problem is.

Answer 1

usersQuery is an IEnumerable<IEnumerable<Plate>> you can either rectify this in your platesQuery like this:

var platesQuery = from plates in usersQuery
                  from plate in plates
                  group plate by plate.Time into grouping
                  select grouping;

Or flatten out the initial results so you have an IEnumerable<Plate> instead:

var usersQuery = from user in Model.Users
                 from plate in user.Plates
                 select plate;