//add manytomany to db
public static CourseTeacher BindTeacherToCourse(int teacherId, int courseId)
{
CoursesEntities db = new CoursesEntities();
if (db.CourseTeachers.Where(p => p.TeacherId == teacherId && p.CourseId == courseId).Count() != 0)
{
return(null);
}
CourseTeacher newCourseTeacher = new CourseTeacher();
newCourseTeacher.CourseId = courseId;
newCourseTeacher.TeacherId = teacherId;
db.CourseTeachers.Add(newCourseTeacher);
try
{
db.SaveChanges();
db.Dispose();
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
return(newCourseTeacher);
}
public static Topic AddTopic(string name, int courseId)
{
CoursesEntities db = new CoursesEntities();
if (db.Topics.Where(p => p.Name == name && p.CourseId == courseId).Count() != 0)
{
return(null);
}
Topic newTopic = new Topic();
newTopic.Name = name;
newTopic.CourseId = courseId;
db.Topics.Add(newTopic);
try
{
db.SaveChanges();
db.Dispose();
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
return(newTopic);
}
public static Student AddStudent(string name, int group, int schoolId)
{
CoursesEntities db = new CoursesEntities();
if (db.Students.Where(p => p.Name == name && p.GroupN == group && p.SchoolId == schoolId).Count() != 0)
{
return(null);
}
Student newStudent = new Student();
newStudent.Name = name;
newStudent.GroupN = group;
newStudent.SchoolId = schoolId;
db.Students.Add(newStudent);
try
{
db.SaveChanges();
db.Dispose();
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
return(newStudent);
}
public static Course AddCourse(int subjectId, int duration, decimal cost)
{
CoursesEntities db = new CoursesEntities();
if (db.Courses.Where(p => p.SubjectId == subjectId && p.Duration == duration && p.Cost == cost).Count() != 0)
{
return(null);
}
Course newCourse = new Course();
newCourse.SubjectId = subjectId;
newCourse.Duration = duration;
newCourse.Cost = cost;
db.Courses.Add(newCourse);
try
{
db.SaveChanges();
db.Dispose();
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
return(newCourse);
}
public static Topic EditTopic(int id, string name, int courseId)
{
CoursesEntities db = new CoursesEntities();
if (db.Topics.Where(p => p.Name == name && p.CourseId == courseId).Count() != 0)
{
return(null);
}
Topic topic = db.Topics.Find(id);
if (topic != null)
{
topic.Name = name;
topic.CourseId = courseId;
try
{
db.SaveChanges();
db.Dispose();
return(topic);
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
}
return(null);
}
public static Student EditStudent(int id, string name, int group, int schoolId)
{
CoursesEntities db = new CoursesEntities();
if (db.Students.Where(p => p.Name == name && p.GroupN == group && p.SchoolId == schoolId).Count() != 0)
{
return(null);
}
Student student = db.Students.Find(id);
if (student != null)
{
student.Name = name;
student.GroupN = group;
student.SchoolId = schoolId;
try
{
db.SaveChanges();
db.Dispose();
return(student);
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
}
return(null);
}
public static Course EditCourse(int id, decimal cost, int duration, int subjectId)
{
CoursesEntities db = new CoursesEntities();
if (db.Courses.Where(p => p.SubjectId == subjectId && p.Duration == duration && p.Cost == cost).Count() != 0)
{
return(null);
}
Course course = db.Courses.Find(id);
if (course != null)
{
course.Cost = cost;
course.Duration = duration;
course.SubjectId = subjectId;
try
{
db.SaveChanges();
db.Dispose();
return(course);
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
}
return(null);
}
public static School EditSchool(int id, string name)
{
CoursesEntities db = new CoursesEntities();
if (db.Schools.Where(p => p.Name == name).Count() != 0)
{
return(null);
}
School school = db.Schools.Find(id);
if (school != null)
{
school.Name = name;
try
{
db.SaveChanges();
db.Dispose();
return(school);
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
}
return(null);
}
public static Subject EditSubject(int id, string name)
{
CoursesEntities db = new CoursesEntities();
if (db.Subjects.Where(p => p.Name == name).Count() != 0)
{
return(null);
}
Subject subject = db.Subjects.Find(id);
if (subject != null)
{
subject.Name = name;
try
{
db.SaveChanges();
db.Dispose();
return(subject);
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
}
return(null);
}
//edit db
public static Teacher EditTeacher(int id, string name)
{
CoursesEntities db = new CoursesEntities();
if (db.Teachers.Where(p => p.Name == name).Count() != 0)
{
return(null);
}
Teacher teacher = db.Teachers.Find(id);
if (teacher != null)
{
teacher.Name = name;
try
{
db.SaveChanges();
db.Dispose();
return(teacher);
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
}
return(null);
}
public static bool DelBindStudentToCourse(int id)
{
CoursesEntities db = new CoursesEntities();
CourseStudent courseStudent = db.CourseStudents.Find(id);
if (courseStudent != null)
{
db.CourseStudents.Remove(courseStudent);
try
{
db.SaveChanges();
db.Dispose();
return(true);
}
catch (Exception)
{
db.Dispose();
return(false);
}
}
return(false);
}
//delete manytomany from db
public static bool DelBindTeacherToCourse(int id)
{
CoursesEntities db = new CoursesEntities();
CourseTeacher courseTeacher = db.CourseTeachers.Find(id);
if (courseTeacher != null)
{
db.CourseTeachers.Remove(courseTeacher);
try
{
db.SaveChanges();
db.Dispose();
return(true);
}
catch (Exception)
{
db.Dispose();
return(false);
}
}
return(false);
}
public static bool DelTopic(int id)
{
CoursesEntities db = new CoursesEntities();
Topic topic = db.Topics.Find(id);
if (topic != null)
{
db.Topics.Remove(topic);
try
{
db.SaveChanges();
db.Dispose();
return(true);
}
catch (Exception)
{
db.Dispose();
return(false);
}
}
return(false);
}
public static bool DelSubject(int id)
{
CoursesEntities db = new CoursesEntities();
Subject subject = db.Subjects.Find(id);
if (subject != null)
{
db.Subjects.Remove(subject);
try
{
db.SaveChanges();
db.Dispose();
return(true);
}
catch (Exception)
{
db.Dispose();
return(false);
}
}
return(false);
}
public static bool DelSchool(int id)
{
CoursesEntities db = new CoursesEntities();
School school = db.Schools.Find(id);
if (school != null)
{
db.Schools.Remove(school);
try
{
db.SaveChanges();
db.Dispose();
return(true);
}
catch (Exception)
{
db.Dispose();
return(false);
}
}
return(false);
}
//edit manytomany db
public static CourseStudent EditBindStudentToCourse(int id, bool isPaid, int?sertificateNumber)
{
CoursesEntities db = new CoursesEntities();
CourseStudent courseStudent = db.CourseStudents.Find(id);
if (courseStudent != null)
{
courseStudent.IsPaid = isPaid;
courseStudent.SertificateNumber = sertificateNumber;
try
{
db.SaveChanges();
db.Dispose();
return(courseStudent);
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
}
return(null);
}
public static CourseStudent BindStudentToCourse(int studentId, int courseId)
{
CoursesEntities db = new CoursesEntities();
//if (db.CourseStudents.Where(p => p.StudentId == studentId && p.CourseId == courseId).Count() != 0)
// return null;
CourseStudent newCourseStudent = new CourseStudent();
newCourseStudent.CourseId = courseId;
newCourseStudent.StudentId = studentId;
newCourseStudent.IsPaid = false;
db.CourseStudents.Add(newCourseStudent);
try
{
db.SaveChanges();
db.Dispose();
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
return(newCourseStudent);
}
public static Subject AddSubject(string name)
{
CoursesEntities db = new CoursesEntities();
if (db.Subjects.Where(p => p.Name == name).Count() != 0)
{
return(null);
}
Subject newSubject = new Subject();
newSubject.Name = name;
db.Subjects.Add(newSubject);
try
{
db.SaveChanges();
db.Dispose();
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
return(newSubject);
}
//add to db
public static Teacher AddTeacher(string name)
{
CoursesEntities db = new CoursesEntities();
if (db.Teachers.Where(p => p.Name == name).Count() != 0)
{
return(null);
}
Teacher newTeacher = new Teacher();
newTeacher.Name = name;
db.Teachers.Add(newTeacher);
try
{
db.SaveChanges();
db.Dispose();
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
db.Dispose();
return(null);
}
return(newTeacher);
}
