Inheritance: System.Data.Linq.DataContext
 public static bool IsEnrolled(int studentId, int subjectId)
 {
     using (var db = new DerpUniversityDataContext())
     {
         var student = db.Students.First(s => s.Id == studentId);
         return student.StudentSubjectEnrolments.Any(sse => sse.SubjectId == subjectId);
     }
 }
 /// <summary>
 /// Searches for a student by name.
 /// </summary>
 /// <param name="name">Any Part of the first name or last name of the student.</param>
 /// <returns></returns>
 public static Student[] SearchStudents(string name)
 {
     using (var db = new DerpUniversityDataContext())
     {
         var students = db.Students
                          .Where(s => s.LastName.Contains(name))
                          .ToArray();
         return students;
     }
 }
 public static Subject[] GetStudentEnrolments(int id)
 {
     using (var db = new DerpUniversityDataContext())
     {
         var subjects = db.Students
                          .First(s => s.Id == id)
                          .StudentSubjectEnrolments
                          .Select(sse => sse.Subject)
                          .ToArray();
         return subjects;
     }
 }