public static List<Test> GetAllTests()
{
var db = new TestSystemEntities();
var tests = db.Tests.ToList();
db.Dispose();
return tests;
}
public static Test GetTest(int id)
{
var db = new TestSystemEntities();
var test = db.Tests
.Include(p => p.TestQuestions.Select(a => a.Question))
.Where(t => t.Id == id)
.FirstOrDefault();
return test;
}
public static void DeleteQuestion(int id)
{
using (var db = new TestSystemEntities())
{
db.StudentAnswers.RemoveRange(db.StudentAnswers.Where(s => s.QuestionId == id));
db.TestQuestions.Remove(db.TestQuestions.Where(q => q.QuestionId == id).FirstOrDefault());
db.Questions.Remove(db.Questions.Where(q => q.Id == id).FirstOrDefault());
db.SaveChanges();
}
}
public static void UpdateTest(Test test)
{
using (var db = new TestSystemEntities())
{
db.Tests.Add(test);
var entry = db.Entry(test);
entry.State = EntityState.Modified;
db.SaveChanges();
}
}
public static void UpdateTestQuestions(Question[] questions)
{
if (questions == null) return;
using (var db = new TestSystemEntities())
{
foreach (var item in questions)
{
db.Questions.Add(item);
var entry = db.Entry(item);
entry.State = EntityState.Modified;
}
db.SaveChanges();
}
}
public static void AddQuestion(int test, Question q)
{
using (var db = new TestSystemEntities())
{
db.Questions.Add(q);
var entry = db.Entry(q);
entry.State = EntityState.Added;
db.SaveChanges();
TestQuestion t = new TestQuestion()
{
QuestionId = q.Id,
TestId = test
};
db.TestQuestions.Add(t);
db.SaveChanges();
}
}
public static void AddAnswers(List<StudentAnswer> answers)
{
using (var db = new TestSystemEntities())
{
foreach (var item in answers)
{
db.StudentAnswers.Add(item);
}
db.SaveChanges();
}
}
public static int AddStudent(string p, int test)
{
var db = new TestSystemEntities();
Student stud = new Student(){
Name = p,
TestId = test
};
db.Students.Add(stud);
db.SaveChanges();
db.Dispose();
return stud.Id;
}
public static User GetUser(string username, string password)
{
var db = new TestSystemEntities();
var user = db.Users.Where(u => u.Username == username && u.Password == password).FirstOrDefault();
db.Dispose();
return user;
}
public static int AddNewTest(string title)
{
Test t = new Test()
{
Title = title
};
using (var db = new TestSystemEntities())
{
db.Tests.Add(t);
db.SaveChanges();
}
return t.Id;
}
public static void DeleteTest(int id)
{
var db = new TestSystemEntities();
var test = db.Tests.Where(t => t.Id == id).FirstOrDefault();;
var students = db.Students.Where(s => s.TestId == id).ToList();
foreach (var stud in students)
{
db.StudentAnswers.RemoveRange(db.StudentAnswers.Where(s => s.StudentId == stud.Id));
db.Students.Remove(db.Students.Where(s => s.Id == stud.Id).FirstOrDefault());
}
var questions = db.TestQuestions.Where(t => t.TestId == test.Id).Select(s => s.Question).ToList();
db.TestQuestions.RemoveRange(db.TestQuestions.Where(t => t.TestId == test.Id));
db.Questions.RemoveRange(questions);
db.Tests.Remove(test);
db.SaveChanges();
db.Dispose();
}
public static List<Student> GetStudents(int id)
{
var db = new TestSystemEntities();
var students = db.Students.Where(s => s.TestId == id).ToList();
db.Dispose();
return students;
}
public static List<StudentAnswer> GetStudentAnswers(int id)
{
var db = new TestSystemEntities();
var answers = db.StudentAnswers
.Include(m => m.Question)
.Include(q => q.Student)
.Where(s => s.StudentId == id)
.OrderBy(o => o.QuestionId)
.ToList();
db.Dispose();
return answers;
}
