public void UpDateStudent(string IndexNumber, string FirstName, string LastName, string BirthDate, int IdEnrollment)
        {
            var myContext  = new s17975Context();
            var newStudent = new Student();

            newStudent.IndexNumber  = IndexNumber;
            newStudent.FirstName    = FirstName;
            newStudent.LastName     = LastName;
            newStudent.BirthDate    = DateTime.ParseExact(BirthDate, "yyyy-MM-dd", CultureInfo.InvariantCulture);;
            newStudent.IdEnrollment = IdEnrollment;

            myContext.Attach(newStudent);
            myContext.SaveChanges();
        }
        public string DeleteStudent(string indexNumber)
        {
            var myContext = new s17975Context();
            // IndexNumber istnieje ?
            Student student = myContext.Student
                              .Where(student => student.IndexNumber.Equals(indexNumber)).FirstOrDefault();

            if (student == null)
            {
                return("Student nie istnieje !");
            }
            else
            {
                // Jeżeli tak -> usuń
                myContext.Student.Remove(student);
                myContext.SaveChanges();
                return("Usuwanie ukończone, usunięto : " + indexNumber);
            }
        }
        public Response_Enrollment EnrollStudent(Request_EnrollStudent request)
        {
            var myContext = new s17975Context();

            Response_Enrollment response = new Response_Enrollment();
            var studies   = request.Studies;
            var student   = new Student();
            int idstudies = 0;

            student.FirstName   = request.FirstName;
            student.LastName    = request.LastName;
            student.IndexNumber = request.IndexNumber;
            student.BirthDate   = request.BirthDate;

            //1. Czy studia istnieja?
            try
            {
                idstudies = myContext.Studies
                            .Where(idstudies => idstudies.Name.Equals(studies))
                            .FirstOrDefault()
                            .IdStudy;
            } catch (Exception ex)
            {
                throw new Exception("Wybrene studia nie istnieją !");
            }
            Console.WriteLine("IDStudy :" + idstudies);

            //2. Obecne ID Enrollment?
            try
            {
                student.IdEnrollment = myContext.Enrollment
                                       .Max(e => e.IdEnrollment) + 1;
            } catch (Exception ex)
            {
                student.IdEnrollment = 1;
            }
            Console.WriteLine("IDEnr :" + student.IdEnrollment);
            //3. IndexNumer unikalny?
            try
            {
                var indexExists = myContext.Student
                                  .Where(d => d.IndexNumber.Equals(student.IndexNumber))
                                  .FirstOrDefault()
                                  .IndexNumber;

                throw new Exception("IndexNumber już istnieje !");
            }
            catch (Exception ex)
            {
                Console.WriteLine("index nie istnieje");
            }
            //4. Wpis już istnieje?
            Boolean exists_Enrollment = false;

            try
            {
                student.IdEnrollment = myContext.Enrollment
                                       .Where(d => d.IdStudy.Equals(idstudies) && d.Semester == 1)
                                       .FirstOrDefault()
                                       .IdEnrollment;
                exists_Enrollment = true;
            } catch (Exception ex)
            {
                Console.WriteLine("wpis nie istnieje");
            }
            //5. Dodanie enrollment jeżeli nie istnieje
            if (!exists_Enrollment)
            {
                var newEnrollments = new Enrollment();

                newEnrollments.IdEnrollment = student.IdEnrollment;
                newEnrollments.Semester     = 1;
                newEnrollments.IdStudy      = idstudies;
                newEnrollments.StartDate    = DateTime.Now;
                myContext.Add(newEnrollments);
                myContext.SaveChanges();
            }
            //6. Dodanie studenta
            var newStudent = new Student();

            newStudent.IndexNumber  = student.IndexNumber;
            newStudent.FirstName    = student.FirstName;
            newStudent.LastName     = student.LastName;
            newStudent.BirthDate    = student.BirthDate;
            newStudent.IdEnrollment = student.IdEnrollment;

            response.Semester     = 1;
            response.IdEnrollment = student.IdEnrollment;
            response.IdStudy      = idstudies;
            response.StartDate    = DateTime.Now;
            return(response);
        }