public void removeCourse()
{
int idToBeDeleted = idInput("of the student to be deleted");
using (StudentiEntities studentiEntities = new StudentiEntities())
{
Predmeti courseToBeDeleted = studentiEntities.Predmeti.FirstOrDefault(c => c.Id == idToBeDeleted);
if (courseToBeDeleted != null)
{
IEnumerable <Studenti> studentis =
from Studenti in studentiEntities.Studenti
select Studenti;
foreach (Studenti student in studentis)
{
if (student.Predmeti.Contains(courseToBeDeleted))
{
student.Predmeti.Remove(courseToBeDeleted);
}
}
studentiEntities.Predmeti.Remove(courseToBeDeleted);
studentiEntities.SaveChanges();
}
else
{
Console.WriteLine("Course with given ID does not exist!");
}
}
}
public void updateStudentCourses()
{
int studentId, subjectId;
string addOrRemoveCourses;
studentId = idInput("of the student to be updated");
while (true)
{
Console.WriteLine("Enter 1 to remove courses, enter 2 to add courses");
addOrRemoveCourses = Console.ReadLine().Trim();
if (addOrRemoveCourses == "1" || addOrRemoveCourses == "2")
{
break;
}
}
subjectId = idInput("of the subject");
using (StudentiEntities studentiEntities = new StudentiEntities())
{
bool idExists = false;
Studenti studentToBeUpdated = studentiEntities.Studenti.FirstOrDefault(s => s.Id == studentId);
Predmeti subjectToBeAddedOrRemoved = studentiEntities.Predmeti.FirstOrDefault(p => p.Id == subjectId);
if (studentToBeUpdated != null && subjectToBeAddedOrRemoved != null)
{
idExists = true;
}
if (addOrRemoveCourses == "1" && idExists)
{
studentToBeUpdated.Predmeti.Remove(subjectToBeAddedOrRemoved);
subjectToBeAddedOrRemoved.Studenti.Remove(studentToBeUpdated);
studentiEntities.SaveChanges();
}
else if (addOrRemoveCourses == "2" && idExists)
{
studentToBeUpdated.Predmeti.Add(subjectToBeAddedOrRemoved);
subjectToBeAddedOrRemoved.Studenti.Add(studentToBeUpdated);
studentiEntities.SaveChanges();
}
if (!idExists)
{
Console.WriteLine("Invalid IDs!");
}
}
}
public void addNewCourse()
{
Predmeti newCourse = new Predmeti();
Console.WriteLine("Please insert the new subject name");
newCourse.Naziv = Console.ReadLine().Trim();
using (StudentiEntities studentiEntities = new StudentiEntities())
{
studentiEntities.Predmeti.Add(newCourse);
studentiEntities.SaveChanges();
}
}
public void updateCourse()
{
int idToBeUpdated = idInput("of the course to be updated");
string nameUpdated;
Console.WriteLine("Please insert the new course name");
nameUpdated = Console.ReadLine().Trim();
using (StudentiEntities studentiEntities = new StudentiEntities())
{
Predmeti courseToBeUpdated = studentiEntities.Predmeti.FirstOrDefault(c => c.Id == idToBeUpdated);
if (courseToBeUpdated != default)
{
courseToBeUpdated.Naziv = nameUpdated;
studentiEntities.SaveChanges();
}
else
{
Console.WriteLine("Course with given Id does not exist!");
}
}
}
static void Main(string[] args)
{
Predmeti newPredmet = new Predmeti();
HelperClass helperClass = new HelperClass();
while (true)
{
string input;
Console.WriteLine("Select one of the options");
Console.WriteLine("1 - add a new student");
Console.WriteLine("2 - delete a student");
Console.WriteLine("3 - update a student personal information");
Console.WriteLine("4 - update the courses a student in enrolled to");
Console.WriteLine("5 - add a new course");
Console.WriteLine("6 - delete a course");
Console.WriteLine("7 - update a course");
Console.WriteLine("8 - show all students and classes they are enrolled to");
Console.WriteLine("9 - show all courses where a student is enrolled");
Console.WriteLine("10 - exit");
input = Console.ReadLine().Trim();
switch (input)
{
case "1":
helperClass.AddNewStudent();
break;
case "2":
helperClass.DeleteStudent();
break;
case "3":
helperClass.updateStudentInfo();
break;
case "4":
helperClass.updateStudentCourses();
break;
case "5":
helperClass.addNewCourse();
break;
case "6":
helperClass.removeCourse();
break;
case "7":
helperClass.updateCourse();
break;
case "8":
helperClass.showAllStudentsEnrolled();
break;
case "9":
helperClass.showAllCoursesEndrolled();
break;
default:
Environment.Exit(0);
break;
}
}
}