private static void AddStudent(string firstName, string lastName, DateTime enrollmentDate, UniversityModelFirstDbContext customDbContext = null) { UniversityModelFirstDbContext db = null; try { db = customDbContext ?? new UniversityModelFirstDbContext(); var student = new Student { LastName = lastName, FirstName = firstName, EnrollmentDate = enrollmentDate }; db.Students.Add(student); db.SaveChanges(); Console.WriteLine("Added..."); } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { if (customDbContext == null) { db?.Dispose(); } } }
private static IEnumerable <string> ListStudents(UniversityModelFirstDbContext customDbContext = null) { var students = new LinkedList <string>(); UniversityModelFirstDbContext db = null; try { db = customDbContext ?? new UniversityModelFirstDbContext(); var query = from b in db.Students orderby b.ID select b; foreach (var item in query) { students.AddLast($"{item.ID} - {item.FirstName} {item.LastName}"); } } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { if (customDbContext == null) { db?.Dispose(); } } return(students); }
private static void ModifyStudent(string filterFirstName, string newFirstName = null, string newLastName = null, UniversityModelFirstDbContext customDbContext = null) { UniversityModelFirstDbContext db = null; try { db = customDbContext ?? new UniversityModelFirstDbContext(); var student = (from d in db.Students where d.FirstName == filterFirstName select d).Single(); student.LastName = string.IsNullOrEmpty(newLastName) ? student.LastName : newLastName; student.FirstName = string.IsNullOrEmpty(newFirstName) ? student.FirstName : newFirstName; db.SaveChanges(); Console.WriteLine("Modified..."); } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { if (customDbContext == null) { db?.Dispose(); } } }
private static void DeleteStudent(string filterFirstName, UniversityModelFirstDbContext customDbContext = null) { UniversityModelFirstDbContext db = null; try { db = customDbContext ?? new UniversityModelFirstDbContext(); var student = (from d in db.Students where d.FirstName == filterFirstName select d).Single(); db.Students.Remove(student); db.SaveChanges(); Console.WriteLine("Deleted..."); } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { if (customDbContext == null) { db?.Dispose(); } } }