protected void GetCourse()
{
//populate form with existing student record
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
//connect to db via EF
using (comp2007Entities db = new comp2007Entities())
{
//populate a Course instance with the CourseID from the URL parameter
Course c = (from objC in db.Courses
where objC.CourseID == CourseID
select objC).FirstOrDefault();
//map the student properties to the form controls if we found a match
if (c != null)
{
txtCourseTitle.Text = c.Title;
txtCredits.Text = c.Credits.ToString();
}
//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 cr in db.Courses on en.CourseID equals cr.CourseID
join d in db.Departments on cr.DepartmentID equals d.DepartmentID
join s in db.Students on en.StudentID equals s.StudentID
select new { en.EnrollmentID, s.LastName, s.FirstMidName, c.Title, d.Name });
grdStudents.DataSource = objE.ToList();
grdStudents.DataBind();
}
}
protected void GetDepartment()
{
// populate form
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
//Connect
using (comp2007Entities db = new comp2007Entities())
{
Department d = (from objd in db.Departments
where objd.DepartmentID == DepartmentID
select objd).FirstOrDefault();
//Map student to controls
if (d != null)
{
txtDeptName.Text = d.Name;
txtBudget.Text = d.Budget.ToString();
}
//Courses - this code goes in the same method that populates
//the student form but below the existing code that's already in GetDepartment()
var objC = (from c in db.Courses
select new { c.CourseID, c.Title, c.Department.Name });
grdcourses.DataSource = objC.ToList();
grdcourses.DataBind();
}
}
protected void GetCourses()
{
using (comp2007Entities db = new comp2007Entities())
{
String SortString = Session["SortColumn"].ToString() + " " + Session["SortDirection"].ToString();
var Courses = from c in db.Courses
select new { c.CourseID, c.Title, c.Credits, c.Department.Name };
grdCourses.DataSource = Courses.AsQueryable().OrderBy(SortString).ToList();
grdCourses.DataBind();
}
}
protected void GetStudents()
{
//connect to EF
using (comp2007Entities db = new comp2007Entities())
{
String SortString = Session["SortColumn"].ToString() + " " + Session["SortDirection"].ToString();
//query the students table using EF and LINQ
var Students = from s in db.Students
select s;
//bind the result to the gridview
grdStudents.DataSource = Students.AsQueryable().OrderBy(SortString).ToList();
grdStudents.DataBind();
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//use EF to connect to SQL Server
using (comp2007Entities db = new comp2007Entities())
{
//use the Student model to save the new record
Department d = new Department();
d.Name = txtDeptName.Text;
d.Budget = Convert.ToDecimal(txtBudget.Text);
db.Departments.Add(d);
db.SaveChanges();
//redirect to the updated students page
Response.Redirect("departments.aspx");
}
}
protected void grdCourses_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//get selected course ID
Int32 CourseID = Convert.ToInt32(grdCourses.DataKeys[e.RowIndex].Values["CourseID"]);
using (comp2007Entities db = new comp2007Entities())
{
//get selected course
Course objC = (from c in db.Courses
where c.CourseID == CourseID
select c).FirstOrDefault();
//delete
db.Courses.Remove(objC);
db.SaveChanges();
//refresh grid
GetCourses();
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//use EF to connect to SQL Server
using (comp2007Entities db = new comp2007Entities())
{
//use the Student model to save the new record
Course c = new Course();
Int32 CourseID = 0;
//check the querystring for an id so we can determine add / update
if (Request.QueryString["CourseID"] != null)
{
//get the id from the url
CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
//get the current student from EF
c = (from objS in db.Courses
where objS.CourseID == CourseID
select objS).FirstOrDefault();
}
c.Title = txtCourseTitle.Text;
c.Credits = Convert.ToInt32(txtCredits.Text);
//call add only if we have no student ID
if (CourseID == 0)
{
db.Courses.Add(c);
}
//run the update or insert
db.SaveChanges();
//redirect to the updated students page
Response.Redirect("courses.aspx");
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//get selected record id
Int32 EnrollmentID = Convert.ToInt32(grdStudents.DataKeys[e.RowIndex].Values["EnrollmentID"]);
using (comp2007Entities db = new comp2007Entities())
{
//get selected record
Enrollment objE = (from en in db.Enrollments
where en.EnrollmentID == EnrollmentID
select en).FirstOrDefault();
//delete
db.Enrollments.Remove(objE);
db.SaveChanges();
//refresh the data on the page
GetCourse();
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//store which row was clicked
Int32 selectedRow = e.RowIndex;
//get the select student ID using the grids data key collection
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[selectedRow].Values["StudentID"]);
//connect to EF to remove student from db
using (comp2007Entities db = new comp2007Entities())
{
Student s = (from objs in db.Students
where objs.StudentID == StudentID
select objs).FirstOrDefault();
//Delete
db.Students.Remove(s);
db.SaveChanges();
}
// refresh the grid
GetStudents();
}
