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();
}
}
}