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C# Entity Framework Basics LINQ Queries Sorting a Query

Posted by Michael Fazio
Michael Fazio
15,586 Points

Update GetCourses in Repository.cs Help. What am I missing here? Thanks.

Hi - I believe I have correctly updated the Repository.cs file - what am I missing? Thanks for the help.

Course.cs 
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace Treehouse.CodeChallenges
{
    public class Course
    {
        public Course()
        {
            Students = new List<CourseStudent>();
        }

        public int Id { get; set; }
        public int TeacherId { get; set; }
        [Required, StringLength(200)]
        public string Title { get; set; }
        public string Description { get; set; }
        public int Length { get; set; }

        public Teacher Teacher { get; set; }
        public ICollection<CourseStudent> Students { get; set; }
    }
}
Repository.cs 
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;

namespace Treehouse.CodeChallenges
{
    public static class Repository
    {
        public static List<Course> GetCourses()
        {
            using (var context = new Context())
            {
                return context.Courses.ToList(); 
                              .OrderBy(c => c.Teacher.LastName)
                              .ThenBy(c => c.Teacher.FirstName)

            }
        }

        public static List<Course> GetCoursesByTeacher(string lastName)
        {
            using (var context = new Context())
            {
                return context.Courses
                              .Where(c => c.Teacher.LastName == lastName)
                              .ToList();
            }
        }
    }
}
Teacher.cs 
namespace Treehouse.CodeChallenges
{
    public class Teacher
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }
}
Justin Horner
Justin Horner
Treehouse Guest Teacher
Justin Horner
Justin Horner
Treehouse Guest Teacher

Hi Michael,

Please let us know if you have other questions after resolving the issues that Steven Parker listed below. If you need help with making suggested changes, I'd be happy to help.

2 Answers

Steven Parker
Steven Parker
231,072 Points
Steven Parker
Steven Parker
231,072 Points

You're very close, but I see two issues:

  • the semicolon should be moved from the end of the first line to the end of the whole statement
  • the conversion to a list should be done last, after the LINQ functions
Tanmoy Chowdhury
Tanmoy Chowdhury
12,622 Points
Tanmoy Chowdhury
Tanmoy Chowdhury
12,622 Points
filename="Repository.cs" 
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;

namespace Treehouse.CodeChallenges
{
    public static class Repository
    {
        public static List<Course> GetCourses()
        {
            using (var context = new Context())
            {
                return context.Courses.OrderBy(c => c.Teacher.LastName).ThenBy(c => c.Teacher.FirstName).ToList();
            }
        }

        public static List<Course> GetCoursesByTeacher(string lastName)
        {
            using (var context = new Context())
            {
                return context.Courses
                              .Where(c => c.Teacher.LastName == lastName)
                              .ToList();
            }
        }
    }
}