protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
try
{
//Store which row was clicked
Int32 selectedRow = e.RowIndex;
//get the selected sudent ID using the grids data key collection
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[selectedRow].Values["StudentID"]);
//use entity to find the object and remove it
using (GetWreckedEntities db = new GetWreckedEntities())
{
Student s = (from objs in db.Students where objs.StudentID == StudentID select objs).FirstOrDefault();
//now we need to do the delete
db.Students.Remove(s);
db.SaveChanges();
}
//refresh the grid
getStudents();
}
catch (System.Exception)
{
Response.Redirect("/Error.aspx");
}
}
protected void GetStudent()
{
try
{
//populate form for edit
//get the ID
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//connec tot he db using Entity
using (GetWreckedEntities db = new GetWreckedEntities())
{
//populate from a student instance with the student ID from the URL params
Student s = (from objs in db.Students where objs.StudentID == StudentID select objs).FirstOrDefault();
//mpa the student properties from the form controls
txtLastName.Text = s.LastName;
txtFirstName.Text = s.FirstMidName;
txtEnrollDate.Text = s.EnrollmentDate.ToShortDateString();
//enrollments - this code goes in the same method that populates the student form but below the existing code that's already in GetStudent()
var objE = (from en in db.Enrollments
join c in db.Courses on en.CourseID equals c.CourseID
join d in db.Departments on c.DepartmentID equals d.DepartmentID
where en.StudentID == StudentID
select new { en.EnrollmentID, en.Grade, c.Title, d.Name });
grdCourses.DataSource = objE.ToList();
grdCourses.DataBind();
}
}
catch (System.Exception)
{
Response.Redirect("/Error.aspx");
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
try
{
using (GetWreckedEntities db = new GetWreckedEntities())
{
Student s = new Student();
Int32 StudentID = 0;
if (Request.QueryString.Count > 0)
{
StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//get the student from the entity ;D
}
s.LastName = txtLastName.Text;
s.FirstMidName = txtFirstName.Text;
s.EnrollmentDate = Convert.ToDateTime(txtEnrollDate.Text);
if (StudentID == 0)
{
db.Students.Add(s);
}
db.SaveChanges();
}
}
catch (System.Exception)
{
Response.Redirect("/Error.aspx");
}
}
protected void getStudents()
{
try
{
using (GetWreckedEntities db = new GetWreckedEntities())
{
//query the students table using entity
var Students = from s in db.Students
select s;
grdStudents.DataSource = Students.ToList();
grdStudents.DataBind();
}
}
catch (System.Exception)
{
Response.Redirect("/Error.aspx");
}
}
protected void getCourses()
{
try
{
using (GetWreckedEntities db = new GetWreckedEntities())
{
//query the students table using entity
var Courses = from c in db.Courses
select new { c.CourseID, c.Title, c.Credits, c.Department.Name };
String SortString = Session["SortColumn"].ToString() + " " + Session["SortDirection"].ToString();
grdCourses.DataSource = Courses.AsQueryable().OrderBy(SortString).ToList();
grdCourses.DataBind();
}
}
catch (System.Exception)
{
Response.Redirect("/Error.aspx");
}
}
protected void grdCourses_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
try
{
Int32 EnrollmentID = Convert.ToInt32(grdCourses.DataKeys[e.RowIndex].Values["EnrollmentID"]);
using (GetWreckedEntities db = new GetWreckedEntities())
{
Enrollment objE = (from en in db.Enrollments
where en.EnrollmentID == EnrollmentID
select en).FirstOrDefault();
db.Enrollments.Remove(objE);
db.SaveChanges();
GetStudent();
}
}
catch (System.Exception)
{
Response.Redirect("/Error.aspx");
}
}
