protected void GetDepartment()
{
//connect
using (ContosoEntities conn = new ContosoEntities())
{
//get id from url parameter and store in a variable
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
var d = (from dep in conn.Departments
where dep.DepartmentID == DepartmentID
select dep).FirstOrDefault();
//populate the form from our department object
txtName.Text = d.Name;
txtBudget.Text = d.Budget.ToString();
var objE = (from dep in conn.Departments
join c in conn.Courses on dep.DepartmentID equals c.DepartmentID
where dep.DepartmentID == DepartmentID
select new { c.CourseID, c.Title, dep.Name});
grdCourses.DataSource = objE.ToList();
grdCourses.DataBind();
pnlCourses.Visible = true;
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (ContosoEntities conn = new ContosoEntities())
{
Student s = new Student();
if (Request.QueryString["StudentID"] != null)
{
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
s = (from stu in conn.Students where stu.StudentID == StudentID select stu).FirstOrDefault();
}
s.FirstMidName = txtFirstName.Text;
s.LastName = txtLastName.Text;
s.EnrollmentDate = Convert.ToDateTime(txtEnrollmentDate.Text);
if (Request.QueryString.Count == 0)
{
conn.Students.Add(s);
}
conn.SaveChanges();
Response.Redirect("students.aspx");
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (ContosoEntities conn = new ContosoEntities())
{
//instantiate a new deparment object in memory
Department d = new Department();
//decide if updating or adding, then save
if (Request.QueryString.Count > 0)
{
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
d = (from dep in conn.Departments
where dep.DepartmentID == DepartmentID
select dep).FirstOrDefault();
}
//fill the properties of our object from the form inputs
d.Name = txtName.Text;
d.Budget = Convert.ToDecimal(txtBudget.Text);
if (Request.QueryString.Count == 0)
{
conn.Departments.Add(d);
}
conn.SaveChanges();
//redirect to updated departments page
Response.Redirect("departments.aspx");
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (ContosoEntities conn = new ContosoEntities())
{
//instantiate a new deparment object in memory
Cours c = new Cours();
//decide if updating or adding, then save
if (!String.IsNullOrEmpty(Request.QueryString["CourseID"]))
{
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
c = (from cour in conn.Courses
where cour.CourseID == CourseID
select cour).FirstOrDefault();
}
//fill the properties of our object from the form inputs
c.Title = txtTitle.Text;
c.Credits = Convert.ToInt32(txtCredits.Text);
c.DepartmentID = Convert.ToInt32(ddlDepartments.SelectedValue);
if (String.IsNullOrEmpty(Request.QueryString["CourseID"]))
{
conn.Courses.Add(c);
}
conn.SaveChanges();
//redirect to updated departments page
Response.Redirect("courses.aspx");
}
}
protected void GetStudents()
{
//connect using our connection string from web.config and EF context class
using (ContosoEntities conn = new ContosoEntities())
{
var studs = from s in conn.Students select new { s.StudentID, s.FirstMidName, s.LastName };
String sort = Session["SortColumn"].ToString() + " " + Session["SortDirection"].ToString();
grdStudents.DataSource = studs.AsQueryable().OrderBy(sort).ToList();
grdStudents.DataBind();
}
}
protected void GetStudent()
{
//connect
using (ContosoEntities db = new ContosoEntities())
{
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//populate a student instance with the StudentID from the URL parameter
Student s = (from objS in db.Students
where objS.StudentID == StudentID
select objS).FirstOrDefault();
//map the student properties to the form controls if we found a match
if (s != null)
{
txtLastName.Text = s.LastName;
txtFirstName.Text = s.FirstMidName;
txtEnrollmentDate.Text = s.EnrollmentDate.ToString("yyyy-MM-dd");
}
//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();
//clear dropdowns
ddlDepartment.ClearSelection();
ddlCourse.ClearSelection();
//fill departments to dropdown
var deps = from d in db.Departments
orderby d.Name
select d;
ddlDepartment.DataSource = deps.ToList();
ddlDepartment.DataBind();
//add default options to the 2 dropdowns
ListItem newItem = new ListItem("-Select-", "0");
ddlDepartment.Items.Insert(0, newItem);
ddlCourse.Items.Insert(0, newItem);
//show the course panel
pnlCourses.Visible = true;
}
}
protected void ddlDepartment_SelectedIndexChanged(object sender, EventArgs e)
{
using (ContosoEntities conn = new ContosoEntities()) {
Int32 DepartmentID = Convert.ToInt32(ddlDepartment.SelectedValue);
var objC = from c in conn.Courses where c.DepartmentID == DepartmentID orderby c.Title select c;
ddlCourse.DataSource = objC.ToList();
ddlCourse.DataBind();
ListItem newItem = new ListItem("-Select-", "0");
ddlCourse.Items.Insert(0, newItem);
}
}
protected void GetDepartments()
{
//connect using our connection string from web.config and EF context class
using (ContosoEntities conn = new ContosoEntities())
{
//use link to query the Departments model
var deps = from d in conn.Departments
select new {d.DepartmentID, d.Name, d.Budget};
//bind the query result to the gridview
String sort = Session["SortColumn"].ToString() + " " + Session["SortDirection"].ToString();
grdDepartments.DataSource = deps.AsQueryable().OrderBy(sort).ToList();
grdDepartments.DataBind();
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//connect
using (ContosoEntities conn = new ContosoEntities())
{
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[e.RowIndex].Values["StudentID"]);
var s = (from stu in conn.Students where stu.StudentID == StudentID select stu).FirstOrDefault();
conn.Students.Remove(s);
conn.SaveChanges();
GetStudents();
}
}
protected void grdCourses_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
Int32 CourseID = Convert.ToInt32(grdCourses.DataKeys[e.RowIndex].Values["CourseID"]);
using (ContosoEntities db = new ContosoEntities())
{
Cours objE = (from c in db.Courses
where c.CourseID == CourseID
select c).FirstOrDefault();
//process the deletion
db.Courses.Remove(objE);
db.SaveChanges();
//repopulate the page
GetDepartment();
}
}
protected void btnAdd_Click(object sender, EventArgs e)
{
using (ContosoEntities conn = new ContosoEntities())
{
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
Int32 StudentID = Convert.ToInt32(ddlStudent.SelectedValue);
Enrollment objE = new Enrollment();
objE.StudentID = StudentID;
objE.CourseID = CourseID;
conn.Enrollments.Add(objE);
conn.SaveChanges();
GetCourse();
}
}
protected void grdDepartments_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//connect
using (ContosoEntities conn = new ContosoEntities())
{
//get the selected DepartmentID
Int32 DepartmentID = Convert.ToInt32(grdDepartments.DataKeys[e.RowIndex].Values["DepartmentID"]);
var d = (from dep in conn.Departments
where dep.DepartmentID == DepartmentID
select dep).FirstOrDefault();
//process the delete
conn.Departments.Remove(d);
conn.SaveChanges();
//update the grid
GetDepartments();
}
}
protected void GetCourse()
{
//connect
using (ContosoEntities conn = new ContosoEntities())
{
//get id from url parameter and store in a variable
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
var c = (from cour in conn.Courses
where cour.CourseID == CourseID
select cour).FirstOrDefault();
//populate the form from our object
txtTitle.Text = c.Title;
txtCredits.Text = c.Credits.ToString();
ddlDepartments.SelectedValue = Convert.ToString(c.DepartmentID);
var objS = (from s in conn.Students
join enr in conn.Enrollments on s.StudentID equals enr.StudentID
join co in conn.Courses on enr.CourseID equals co.CourseID
where enr.CourseID == CourseID
select new {enr.EnrollmentID, s.FirstMidName, s.LastName });
ddlStudent.ClearSelection();
var stus = from s in conn.Students
orderby s.LastName
select new { s.StudentID, Name = string.Concat(s.LastName, ", ", s.FirstMidName)};
ddlStudent.DataSource = stus.ToList();
ddlStudent.DataBind();
ListItem newItem = new ListItem("-Select-", "0");
ddlStudent.Items.Insert(0, newItem);
pnlStudents.Visible = true;
}
}
protected void GetDepartments()
{
//connect using our connection string from web.config and EF context class
using (ContosoEntities conn = new ContosoEntities())
{
//use link to query the Departments model
var deps = from d in conn.Departments
select new { d.DepartmentID, d.Name };
//bind the query result to the ddl
ddlDepartments.DataSource = deps.ToList();
ddlDepartments.DataBind();
}
}
protected void grdCourses_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//get the selected EnrollmentID
Int32 EnrollmentID = Convert.ToInt32(grdCourses.DataKeys[e.RowIndex].Values["EnrollmentID"]);
using (ContosoEntities db = new ContosoEntities())
{
Enrollment objE = (from en in db.Enrollments
where en.EnrollmentID == EnrollmentID
select en).FirstOrDefault();
//process the deletion
db.Enrollments.Remove(objE);
db.SaveChanges();
//repopulate the page
GetStudent();
}
}
