/// <summary>
/// This method gets the Students data from the DB
/// </summary>
private void GetStudentsDetails()
{
int StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
// Connect to Entity FrameWork
using (ControlsoContext db = new ControlsoContext())
{
//Query the Students Table using EF and LINQ
var Students = (from allStudents in db.Students
where allStudents.StudentID == StudentID
select allStudents);
// bind the result to the Student GridView
StudentGridView.DataSource = Students.ToList();
StudentGridView.DataBind();
//Query the Course Table using EF and LINQ
var CoursesDetails = (from allCourse in db.Courses
join enrolment in db.Enrollments
on allCourse.CourseID equals enrolment.CourseID
where enrolment.StudentID == StudentID
select new { CourseID = allCourse.CourseID, Title = allCourse.Title, Grade = enrolment.Grade, Credit = allCourse.Credits });
// bind the result to the Course GridView
StudentCourseView.DataSource = CoursesDetails.ToList();
StudentCourseView.DataBind();
}
}
protected void CourseDetails_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
// Store Which row need to be deleted
int selectedRow = e.RowIndex;
// get the seleceted Enrollment Id
int EnrollmentID = Convert.ToInt32(CourseDetails.DataKeys[selectedRow].Values["EnrollmentID"]);
using (ControlsoContext db = new ControlsoContext())
{
var deleteStudent = (from delStudent in db.Enrollments
where delStudent.EnrollmentID == EnrollmentID
select delStudent);
// Remove Student from Enrolmented course
foreach (var item in deleteStudent)
{
db.Enrollments.Remove(item);
}
db.SaveChanges();
// Refresh the Grid
this.GetStudents();
}
}
/// <summary>
/// This method gets the Students data from the DB
/// </summary>
private void GetStudents()
{
// Connect to Entity FrameWork
using (ControlsoContext db = new ControlsoContext())
{
//Query the Students Table using EF and LINQ
var Students = (from allStudents in db.Students
select allStudents);
// bind the result to the Student GridView
StudentGridView.DataSource = Students.ToList();
StudentGridView.DataBind();
}
}
private void GetStudents()
{
int CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
//
using (ControlsoContext db = new ControlsoContext())
{
// query the Student table using EF and LINQ
var Students = (from allStudents in db.Students
join enrollment in db.Enrollments
on allStudents.StudentID equals enrollment.StudentID
where enrollment.CourseID == CourseID
select new { LastName = allStudents.LastName, FirstMidName = allStudents.FirstMidName, EnrollmentID = enrollment.EnrollmentID });
CourseDetails.DataSource = Students.ToList();
CourseDetails.DataBind();
}
}
protected void SaveButton_Click(object sender, EventArgs e)
{
//use EF to conect to the server
using (ControlsoContext db = new ControlsoContext())
{
//use the student model to create a new students object and
// save a new record
Enrollment addStudent = new Enrollment();
int EnrollmentID = 0;
if (Request.QueryString.Count > 0)//our URL has a StudentID in it
{
// get the id from the URL
/*StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
* //get the Current student from EF bd
* newStudent = (from student in db.Students
* where student.StudentID == StudentID
* select student).FirstOrDefault();*/
}
// add form data th the new student record
addStudent.CourseID = Convert.ToInt32(CourseIDTextBox.Text);
addStudent.StudentID = Convert.ToInt32(StudentIDTextBox.Text);
addStudent.Grade = Convert.ToInt32(GradeTextBox.Text);
//use LINQ to ADO.NET to add / insert students into the db
if (EnrollmentID == 0)
{
db.Enrollments.Add(addStudent);
}
//save our changes -also updates and inserts
db.SaveChanges();
// Redirect back to the update Students page
Response.Redirect("Default.aspx");
}
}
protected void GetStudent()
{
//populated the form with existing data from db
int StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//Connect to the EF DB
using (ControlsoContext db = new ControlsoContext())
{
// populate a student object instance with the studentID
// from the url parameter
Student updateStudent = (from student in db.Students
where student.StudentID == StudentID
select student).FirstOrDefault();
// map the student properties to the form control
if (updateStudent != null)
{
LastNameTextBox.Text = updateStudent.LastName;
FirstNameTextbox.Text = updateStudent.FirstMidName;
EnrollmentDateTextbox.Text = updateStudent.EnrollmentDate.ToString("yyyy-MM-dd");
}
}
}
