// GET: Instructors/Create
 public IActionResult Create()
 {
     var instructor = new Instructor();
     instructor.Courses = new List<CourseAssignment>();
     PopulateAssignedCourseData(instructor);
     return View();
 }
        public ActionResult Create(Instructor instructor)
        {
            if (ModelState.IsValid)
            {
                db.Instructors.Add(instructor);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            ViewBag.PersonID = new SelectList(db.OfficeAssignments, "PersonID", "Location", instructor.PersonID);
            return View(instructor);
        }
        private void UpdateInstructorCourses(int[] selectedCourses, Instructor instructorToUpdate)
        {
            if (selectedCourses == null)
            {
                instructorToUpdate.Courses = new List<Course>();
                return;
            }

            var selectedCoursesHS = new HashSet<int>(selectedCourses);
            var instructorCourses = new HashSet<int>(instructorToUpdate.Courses.Select(c => c.Id));

            foreach (var course in UoW.Courses.GetAll())
            {
                if (selectedCoursesHS.Contains(course.Id))
                {
                    if (!instructorCourses.Contains(course.Id))
                    {
                        instructorToUpdate.Courses.Add(course);
                    }
                }
                else
                {
                    if (instructorCourses.Contains(course.Id))
                    {
                        instructorToUpdate.Courses.Remove(course);
                    }
                }
            }
        }
        private void UpdateInstructorCourses(string[] selectedCourses, Instructor instructorToUpdate)
        {
            if (selectedCourses == null)
            {
                instructorToUpdate.Courses = new List<Course>();
                return;
            }

            var selectedCoursesHS = new HashSet<string>(selectedCourses);
            var instructorCourses = new HashSet<int>
                (instructorToUpdate.Courses.Select(c => c.CourseID));
            foreach (var course in db.Courses)
            {
                if (selectedCoursesHS.Contains(course.CourseID.ToString()))
                {
                    if (!instructorCourses.Contains(course.CourseID))
                    {
                        instructorToUpdate.Courses.Add(course);
                    }
                }
                else
                {
                    if (instructorCourses.Contains(course.CourseID))
                    {
                        instructorToUpdate.Courses.Remove(course);
                    }
                }
            }
        }
 private void PopulateAssignedCourseData(Instructor instructor)
 {
     var allCourses = db.Courses;
     var instructorCourses = new HashSet<int>(instructor.Courses.Select(c => c.CourseID));
     var viewModel = new List<AssignedCourseData>();
     foreach (var course in allCourses)
     {
         viewModel.Add(new AssignedCourseData
         {
             CourseID = course.CourseID,
             Title = course.Title,
             Assigned = instructorCourses.Contains(course.CourseID)
         });
     }
     ViewBag.Courses = viewModel;
 }
        // new fuction to get the classes that are selected from the checkbox to add those classes for the Instructor
        private void UpdateInstructorCourses(string[] selectedCourses, Instructor instructorToUpdate)
        {
            if (selectedCourses == null)
            {
                //If no check boxes were selected, the code in UpdateInstructorCourses initializes the Courses navigation property with an empty collection
                instructorToUpdate.Courses = new List<Course>();
                return;
            }

            var selectedCoursesHS = new HashSet<string>(selectedCourses);
            var instructorCourses = new HashSet<int>(instructorToUpdate.Courses.Select(c => c.CourseID));

            foreach (var course in db.Courses)
            {
                if (selectedCoursesHS.Contains(course.CourseID.ToString()))//if the courses are selected from the checkbox
                {
                    if (!instructorCourses.Contains(course.CourseID))//if the courses that are selected are not in the Instructor.Courses navigation property
                    {
                        instructorToUpdate.Courses.Add(course);
                    }
                }
                else
                {
                    if (instructorCourses.Contains(course.CourseID))// if the corses aren't selected, but they are in the Instructor.Courses navigation property,
                        //and then delete them
                    {
                        instructorToUpdate.Courses.Remove(course);
                    }
                }
            }
        }
        private void PopulateAssignedCourseData(Instructor instructor)
        {
            var allCourses = db.Courses; // db is an iobject that is pointing to SchoolContext Class, and then use db.Courses to access to the
            // fuction Courses in the SchoolContext Class which mean to access to the Course table in the data base
            var instructorCourses = new HashSet<int>(instructor.Courses.Select(c => c.CourseID));//create the mark in the checkbox for the classes
            //base on the PersonID
            var viewModel = new List<AssignedCourseData>();// object viewModel is pointing to AssignedCourseData class, and viewModel is going to
            //use for adding data to the CourseID, Title, and Assigned in the AssignedCourseData class
            foreach (var course in allCourses)// loop through all the classes in the Course table
            {
                viewModel.Add(new AssignedCourseData
                                  {
                                      CourseID = course.CourseID,
                                      Title = course.Title,
                                      Assigned = instructorCourses.Contains(course.CourseID)//get the CourseID base on the Instructor
                                      // Assigned is bool type

                                  });
            }
            ViewBag.Courses = viewModel;
        }
        public static void Initialize(SchoolContext context)
        {
            //context.Database.EnsureCreated();

            // Look for any students.
            if (context.Students.Any())
            {
                return;   // DB has been seeded
            }

            var students = new Student[]
            {
                new Student {
                    FirstMidName   = "Carson", LastName = "Alexander",
                    EnrollmentDate = DateTime.Parse("2010-09-01")
                },
                new Student {
                    FirstMidName   = "Meredith", LastName = "Alonso",
                    EnrollmentDate = DateTime.Parse("2012-09-01")
                },
                new Student {
                    FirstMidName   = "Arturo", LastName = "Anand",
                    EnrollmentDate = DateTime.Parse("2013-09-01")
                },
                new Student {
                    FirstMidName   = "Gytis", LastName = "Barzdukas",
                    EnrollmentDate = DateTime.Parse("2012-09-01")
                },
                new Student {
                    FirstMidName   = "Yan", LastName = "Li",
                    EnrollmentDate = DateTime.Parse("2012-09-01")
                },
                new Student {
                    FirstMidName   = "Peggy", LastName = "Justice",
                    EnrollmentDate = DateTime.Parse("2011-09-01")
                },
                new Student {
                    FirstMidName   = "Laura", LastName = "Norman",
                    EnrollmentDate = DateTime.Parse("2013-09-01")
                },
                new Student {
                    FirstMidName   = "Nino", LastName = "Olivetto",
                    EnrollmentDate = DateTime.Parse("2005-09-01")
                }
            };

            foreach (Student s in students)
            {
                context.Students.Add(s);
            }
            context.SaveChanges();

            var instructors = new Instructor[]
            {
                new Instructor {
                    FirstMidName = "Kim", LastName = "Abercrombie",
                    HireDate     = DateTime.Parse("1995-03-11")
                },
                new Instructor {
                    FirstMidName = "Fadi", LastName = "Fakhouri",
                    HireDate     = DateTime.Parse("2002-07-06")
                },
                new Instructor {
                    FirstMidName = "Roger", LastName = "Harui",
                    HireDate     = DateTime.Parse("1998-07-01")
                },
                new Instructor {
                    FirstMidName = "Candace", LastName = "Kapoor",
                    HireDate     = DateTime.Parse("2001-01-15")
                },
                new Instructor {
                    FirstMidName = "Roger", LastName = "Zheng",
                    HireDate     = DateTime.Parse("2004-02-12")
                }
            };

            foreach (Instructor i in instructors)
            {
                context.Instructors.Add(i);
            }
            context.SaveChanges();

            var departments = new Department[]
            {
                new Department {
                    Name         = "English", Budget = 350000,
                    StartDate    = DateTime.Parse("2007-09-01"),
                    InstructorID = instructors.Single(i => i.LastName == "Abercrombie").ID
                },
                new Department {
                    Name         = "Mathematics", Budget = 100000,
                    StartDate    = DateTime.Parse("2007-09-01"),
                    InstructorID = instructors.Single(i => i.LastName == "Fakhouri").ID
                },
                new Department {
                    Name         = "Engineering", Budget = 350000,
                    StartDate    = DateTime.Parse("2007-09-01"),
                    InstructorID = instructors.Single(i => i.LastName == "Harui").ID
                },
                new Department {
                    Name         = "Economics", Budget = 100000,
                    StartDate    = DateTime.Parse("2007-09-01"),
                    InstructorID = instructors.Single(i => i.LastName == "Kapoor").ID
                }
            };

            foreach (Department d in departments)
            {
                context.Departments.Add(d);
            }
            context.SaveChanges();

            var courses = new Course[]
            {
                new Course {
                    CourseID     = 1050, Title = "Chemistry", Credits = 3,
                    DepartmentID = departments.Single(s => s.Name == "Engineering").DepartmentID
                },
                new Course {
                    CourseID     = 4022, Title = "Microeconomics", Credits = 3,
                    DepartmentID = departments.Single(s => s.Name == "Economics").DepartmentID
                },
                new Course {
                    CourseID     = 4041, Title = "Macroeconomics", Credits = 3,
                    DepartmentID = departments.Single(s => s.Name == "Economics").DepartmentID
                },
                new Course {
                    CourseID     = 1045, Title = "Calculus", Credits = 4,
                    DepartmentID = departments.Single(s => s.Name == "Mathematics").DepartmentID
                },
                new Course {
                    CourseID     = 3141, Title = "Trigonometry", Credits = 4,
                    DepartmentID = departments.Single(s => s.Name == "Mathematics").DepartmentID
                },
                new Course {
                    CourseID     = 2021, Title = "Composition", Credits = 3,
                    DepartmentID = departments.Single(s => s.Name == "English").DepartmentID
                },
                new Course {
                    CourseID     = 2042, Title = "Literature", Credits = 4,
                    DepartmentID = departments.Single(s => s.Name == "English").DepartmentID
                },
            };

            foreach (Course c in courses)
            {
                context.Courses.Add(c);
            }
            context.SaveChanges();

            var officeAssignments = new OfficeAssignment[]
            {
                new OfficeAssignment {
                    InstructorID = instructors.Single(i => i.LastName == "Fakhouri").ID,
                    Location     = "Smith 17"
                },
                new OfficeAssignment {
                    InstructorID = instructors.Single(i => i.LastName == "Harui").ID,
                    Location     = "Gowan 27"
                },
                new OfficeAssignment {
                    InstructorID = instructors.Single(i => i.LastName == "Kapoor").ID,
                    Location     = "Thompson 304"
                },
            };

            foreach (OfficeAssignment o in officeAssignments)
            {
                context.OfficeAssignments.Add(o);
            }
            context.SaveChanges();

            var courseInstructors = new CourseAssignment[]
            {
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Chemistry").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Kapoor").ID
                },
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Chemistry").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Harui").ID
                },
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Microeconomics").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Zheng").ID
                },
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Macroeconomics").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Zheng").ID
                },
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Calculus").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Fakhouri").ID
                },
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Trigonometry").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Harui").ID
                },
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Composition").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Abercrombie").ID
                },
                new CourseAssignment {
                    CourseID     = courses.Single(c => c.Title == "Literature").CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Abercrombie").ID
                },
            };

            foreach (CourseAssignment ci in courseInstructors)
            {
                context.CourseAssignments.Add(ci);
            }
            context.SaveChanges();

            var enrollments = new Enrollment[]
            {
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alexander").ID,
                    CourseID  = courses.Single(c => c.Title == "Chemistry").CourseID,
                    Grade     = Grade.A
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alexander").ID,
                    CourseID  = courses.Single(c => c.Title == "Microeconomics").CourseID,
                    Grade     = Grade.C
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alexander").ID,
                    CourseID  = courses.Single(c => c.Title == "Macroeconomics").CourseID,
                    Grade     = Grade.B
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alonso").ID,
                    CourseID  = courses.Single(c => c.Title == "Calculus").CourseID,
                    Grade     = Grade.B
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alonso").ID,
                    CourseID  = courses.Single(c => c.Title == "Trigonometry").CourseID,
                    Grade     = Grade.B
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alonso").ID,
                    CourseID  = courses.Single(c => c.Title == "Composition").CourseID,
                    Grade     = Grade.B
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Anand").ID,
                    CourseID  = courses.Single(c => c.Title == "Chemistry").CourseID
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Anand").ID,
                    CourseID  = courses.Single(c => c.Title == "Microeconomics").CourseID,
                    Grade     = Grade.B
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Barzdukas").ID,
                    CourseID  = courses.Single(c => c.Title == "Chemistry").CourseID,
                    Grade     = Grade.B
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Li").ID,
                    CourseID  = courses.Single(c => c.Title == "Composition").CourseID,
                    Grade     = Grade.B
                },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Justice").ID,
                    CourseID  = courses.Single(c => c.Title == "Literature").CourseID,
                    Grade     = Grade.B
                }
            };

            foreach (Enrollment e in enrollments)
            {
                var enrollmentInDataBase = context.Enrollments.Where(
                    s =>
                    s.Student.ID == e.StudentID &&
                    s.Course.CourseID == e.CourseID).SingleOrDefault();
                if (enrollmentInDataBase == null)
                {
                    context.Enrollments.Add(e);
                }
            }
            context.SaveChanges();
        }
        private void UpdateInstructorCourses(string[] selectedCourses, Instructor instructor)
        {
            if (selectedCourses == null)
            {
                var condition = new PredicateGroup { Operator = GroupOperator.And, Predicates = new List<IPredicate>() };

                condition.Predicates.Add(Predicates.Field<CourseInstructor>(s => s.InstructorId, Operator.Eq, instructor.InstructorId));

                instructor.Courses.ForEach(c =>
                {
                    condition.Predicates.Add(Predicates.Field<CourseInstructor>(s => s.CourseId, Operator.Eq, c.CourseId));
                });

                _connection.Delete<CourseInstructor>(condition);
            }
            else
            {
                var selectedCourseHs = new HashSet<string>(selectedCourses);
                var instructorCourses = new HashSet<int>(
                    instructor.Courses.Select(s => s.CourseId));

                var courseLst = new List<int>();

                selectedCourses.ToList().ForEach(s =>
                {
                    courseLst.Add(Convert.ToInt32(s));
                });

                instructorCourses.ForEach(s =>
                {
                    courseLst.Add(s);
                });

                foreach (var course in courseLst)
                {
                    if (selectedCourseHs.Contains(course.ToString()))
                    {
                        if (!instructorCourses.Contains(course))
                        {
                            var courseInstructor = new CourseInstructor
                            {
                                InstructorId = instructor.InstructorId,
                                CourseId = course
                            };
                            _connection.Insert(courseInstructor);
                        }
                    }
                    else
                    {
                        if (instructorCourses.Contains(course))
                        {
                            var condition = new PredicateGroup { Operator = GroupOperator.And, Predicates = new List<IPredicate>() };
                            condition.Predicates.Add(Predicates.Field<CourseInstructor>(f => f.InstructorId, Operator.Eq, instructor.InstructorId));
                            condition.Predicates.Add(Predicates.Field<CourseInstructor>(f => f.CourseId, Operator.Eq, course));
                            _connection.Delete<CourseInstructor>(condition);
                        }
                    }
                }
            }
        }
        private void PopulateAssignedCourseData(Instructor instructor)
        {
            var courseLst = GetInstructorCourse(instructor.InstructorId);

            courseLst.ForEach(instructor.AddCourse);

            var allCourses = _connection.GetList<Course>();
            var instructorCourses = new HashSet<int>(instructor.Courses.Select(s => s.CourseId));
            var viewModel = allCourses.Select(course => new AssignedCourseData
            {
                CourseId = course.CourseId,
                Title = course.Title,
                Assigned = instructorCourses.Contains(course.CourseId)
            }).ToList();

            _query.Clear();
            ViewBag.Courses = viewModel;
        }
Example #11
0
        public static void Initialize(SchoolContext context)
        {
            //context.Database.EnsureCreated();

            // Look for any students.
            if (context.Students.Any())
            {
                return;   // DB has been seeded
            }

            var students = new Student[]
            {
                new Student { FirstMidName = "Carson",   LastName = "Alexander",
                    EnrollmentDate = DateTime.Parse("2010-09-01") },
                new Student { FirstMidName = "Meredith", LastName = "Alonso",
                    EnrollmentDate = DateTime.Parse("2012-09-01") },
                new Student { FirstMidName = "Arturo",   LastName = "Anand",
                    EnrollmentDate = DateTime.Parse("2013-09-01") },
                new Student { FirstMidName = "Gytis",    LastName = "Barzdukas",
                    EnrollmentDate = DateTime.Parse("2012-09-01") },
                new Student { FirstMidName = "Yan",      LastName = "Li",
                    EnrollmentDate = DateTime.Parse("2012-09-01") },
                new Student { FirstMidName = "Peggy",    LastName = "Justice",
                    EnrollmentDate = DateTime.Parse("2011-09-01") },
                new Student { FirstMidName = "Laura",    LastName = "Norman",
                    EnrollmentDate = DateTime.Parse("2013-09-01") },
                new Student { FirstMidName = "Nino",     LastName = "Olivetto",
                    EnrollmentDate = DateTime.Parse("2005-09-01") }
            };

            foreach (Student s in students)
            {
                context.Students.Add(s);
            }
            context.SaveChanges();

            var instructors = new Instructor[]
            {
                new Instructor { FirstMidName = "Kim",     LastName = "Abercrombie",
                    HireDate = DateTime.Parse("1995-03-11") },
                new Instructor { FirstMidName = "Fadi",    LastName = "Fakhouri",
                    HireDate = DateTime.Parse("2002-07-06") },
                new Instructor { FirstMidName = "Roger",   LastName = "Harui",
                    HireDate = DateTime.Parse("1998-07-01") },
                new Instructor { FirstMidName = "Candace", LastName = "Kapoor",
                    HireDate = DateTime.Parse("2001-01-15") },
                new Instructor { FirstMidName = "Roger",   LastName = "Zheng",
                    HireDate = DateTime.Parse("2004-02-12") }
            };

            foreach (Instructor i in instructors)
            {
                context.Instructors.Add(i);
            }
            context.SaveChanges();

            var departments = new Department[]
            {
                new Department { Name = "English",     Budget = 350000,
                    StartDate = DateTime.Parse("2007-09-01"),
                    InstructorID  = instructors.Single( i => i.LastName == "Abercrombie").ID },
                new Department { Name = "Mathematics", Budget = 100000,
                    StartDate = DateTime.Parse("2007-09-01"),
                    InstructorID  = instructors.Single( i => i.LastName == "Fakhouri").ID },
                new Department { Name = "Engineering", Budget = 350000,
                    StartDate = DateTime.Parse("2007-09-01"),
                    InstructorID  = instructors.Single( i => i.LastName == "Harui").ID },
                new Department { Name = "Economics",   Budget = 100000,
                    StartDate = DateTime.Parse("2007-09-01"),
                    InstructorID  = instructors.Single( i => i.LastName == "Kapoor").ID }
            };
                
            foreach (Department d in departments)
            {
                context.Departments.Add(d);
            }
            context.SaveChanges();

            var courses = new Course[]
            {
                new Course {CourseID = 1050, Title = "Chemistry",      Credits = 3,
                    DepartmentID = departments.Single( s => s.Name == "Engineering").DepartmentID
                },
                new Course {CourseID = 4022, Title = "Microeconomics", Credits = 3,
                    DepartmentID = departments.Single( s => s.Name == "Economics").DepartmentID
                },
                new Course {CourseID = 4041, Title = "Macroeconomics", Credits = 3,
                    DepartmentID = departments.Single( s => s.Name == "Economics").DepartmentID
                },
                new Course {CourseID = 1045, Title = "Calculus",       Credits = 4,
                    DepartmentID = departments.Single( s => s.Name == "Mathematics").DepartmentID
                },
                new Course {CourseID = 3141, Title = "Trigonometry",   Credits = 4,
                    DepartmentID = departments.Single( s => s.Name == "Mathematics").DepartmentID
                },
                new Course {CourseID = 2021, Title = "Composition",    Credits = 3,
                    DepartmentID = departments.Single( s => s.Name == "English").DepartmentID
                },
                new Course {CourseID = 2042, Title = "Literature",     Credits = 4,
                    DepartmentID = departments.Single( s => s.Name == "English").DepartmentID
                },
            };

            foreach (Course c in courses)
            {
                context.Courses.Add(c);
            }
            context.SaveChanges();

            var officeAssignments = new OfficeAssignment[]
            {
                new OfficeAssignment {
                    InstructorID = instructors.Single( i => i.LastName == "Fakhouri").ID,
                    Location = "Smith 17" },
                new OfficeAssignment {
                    InstructorID = instructors.Single( i => i.LastName == "Harui").ID,
                    Location = "Gowan 27" },
                new OfficeAssignment {
                    InstructorID = instructors.Single( i => i.LastName == "Kapoor").ID,
                    Location = "Thompson 304" },
            };

            foreach (OfficeAssignment o in officeAssignments)
            {
                context.OfficeAssignments.Add(o);
            }
            context.SaveChanges();

            var courseInstructors = new CourseAssignment[]
            {
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Chemistry" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Kapoor").ID
                    },
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Chemistry" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Harui").ID
                    },
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Microeconomics" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Zheng").ID
                    },
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Macroeconomics" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Zheng").ID
                    },
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Calculus" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Fakhouri").ID
                    },
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Trigonometry" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Harui").ID
                    },
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Composition" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Abercrombie").ID
                    },
                new CourseAssignment {
                    CourseID = courses.Single(c => c.Title == "Literature" ).CourseID,
                    InstructorID = instructors.Single(i => i.LastName == "Abercrombie").ID
                    },
            };

            foreach (CourseAssignment ci in courseInstructors)
            {
                context.CourseAssignments.Add(ci);
            }
            context.SaveChanges();

            var enrollments = new Enrollment[]
            {
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alexander").ID,
                    CourseID = courses.Single(c => c.Title == "Chemistry" ).CourseID,
                    Grade = Grade.A
                },
                    new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alexander").ID,
                    CourseID = courses.Single(c => c.Title == "Microeconomics" ).CourseID,
                    Grade = Grade.C
                    },
                    new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alexander").ID,
                    CourseID = courses.Single(c => c.Title == "Macroeconomics" ).CourseID,
                    Grade = Grade.B
                    },
                    new Enrollment {
                        StudentID = students.Single(s => s.LastName == "Alonso").ID,
                    CourseID = courses.Single(c => c.Title == "Calculus" ).CourseID,
                    Grade = Grade.B
                    },
                    new Enrollment {
                        StudentID = students.Single(s => s.LastName == "Alonso").ID,
                    CourseID = courses.Single(c => c.Title == "Trigonometry" ).CourseID,
                    Grade = Grade.B
                    },
                    new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Alonso").ID,
                    CourseID = courses.Single(c => c.Title == "Composition" ).CourseID,
                    Grade = Grade.B
                    },
                    new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Anand").ID,
                    CourseID = courses.Single(c => c.Title == "Chemistry" ).CourseID
                    },
                    new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Anand").ID,
                    CourseID = courses.Single(c => c.Title == "Microeconomics").CourseID,
                    Grade = Grade.B
                    },
                new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Barzdukas").ID,
                    CourseID = courses.Single(c => c.Title == "Chemistry").CourseID,
                    Grade = Grade.B
                    },
                    new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Li").ID,
                    CourseID = courses.Single(c => c.Title == "Composition").CourseID,
                    Grade = Grade.B
                    },
                    new Enrollment {
                    StudentID = students.Single(s => s.LastName == "Justice").ID,
                    CourseID = courses.Single(c => c.Title == "Literature").CourseID,
                    Grade = Grade.B
                    }
            };

            foreach (Enrollment e in enrollments)
            {
                var enrollmentInDataBase = context.Enrollments.Where(
                    s =>
                            s.Student.ID == e.StudentID &&
                            s.Course.CourseID == e.CourseID).SingleOrDefault();
                if (enrollmentInDataBase == null)
                {
                    context.Enrollments.Add(e);
                }
            }
            context.SaveChanges();
        }
        private void UpdateInstructorCourses(string[] selectedCourses, Instructor instructorToUpdate)
        {
            if (selectedCourses == null)
            {
                instructorToUpdate.Courses = new List<CourseAssignment>();
                return;
            }

            var selectedCoursesHS = new HashSet<string>(selectedCourses);
            var instructorCourses = new HashSet<int>
                (instructorToUpdate.Courses.Select(c => c.Course.CourseID));
            foreach (var course in _context.Courses)
            {
                if (selectedCoursesHS.Contains(course.CourseID.ToString()))
                {
                    if (!instructorCourses.Contains(course.CourseID))
                    {
                        instructorToUpdate.Courses.Add(new CourseAssignment { InstructorID = instructorToUpdate.ID, CourseID = course.CourseID });
                    }
                }
                else
                {

                    if (instructorCourses.Contains(course.CourseID))
                    {
                        CourseAssignment courseToRemove = instructorToUpdate.Courses.SingleOrDefault(i => i.CourseID == course.CourseID);
                        _context.Remove(courseToRemove);
                    }
                }
            }
        }
 public ActionResult Edit(Instructor instructor)
 {
     if (ModelState.IsValid)
     {
         db.Entry(instructor).State = EntityState.Modified;
         db.SaveChanges();
         return RedirectToAction("Index");
     }
     ViewBag.InstructorID = new SelectList(db.OfficeAssignments, "InstructorID", "Location", instructor.InstructorID);
     return View(instructor);
 }