protected void GetDepartment()
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//get the department id
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
//get department info
var d = (from dep in conn.Departments
where dep.DepartmentID == DepartmentID
select dep).FirstOrDefault();
//populate the form
txtName.Text = d.Name;
txtBudget.Text = d.Budget.ToString();
var objC = (from c in conn.Courses
where c.DepartmentID == DepartmentID
select new {c.Title, c.DepartmentID, c.CourseID, c.Credits});
grdDepCourses.DataSource = objC.ToList();
grdDepCourses.DataBind();
//show the course panel
pnlCourses.Visible = true;
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//instantiate a new student object in memory
Student s = new Student();
//decide if updating or adding, then save
if (Request.QueryString.Count > 0)
{
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
s = (from stu in conn.Students
where stu.StudentID == StudentID
select stu).FirstOrDefault();
}
//fill the properties of our object from the form inputs
s.FirstMidName = txtFirstName.Text;
s.LastName = txtLastName.Text;
s.EnrollmentDate = Convert.ToDateTime(txtEnrollDate.Text);
if (Request.QueryString.Count == 0)
{
conn.Students.Add(s);
}
conn.SaveChanges();
//redirect to updated departments page
Response.Redirect("students.aspx");
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//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 (DefaultConnection conn = new DefaultConnection())
{
//instantiate a new student object in memory
Course c = new Course();
//decide if updating or adding, then save
if (!String.IsNullOrEmpty(Request.QueryString["CourseID"]))
{
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
c = (from crs in conn.Courses
where crs.CourseID == CourseID
select crs).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(ddlDepartment.SelectedValue);
if (Request.QueryString.Count == 0)
{
conn.Courses.Add(c);
}
conn.SaveChanges();
//redirect to updated departments page
Response.Redirect("Courses.aspx");
}
}
protected void GetDepartments()
{
//connect using our connection string from web.config and EF context class
using (DefaultConnection conn = new DefaultConnection())
{
//use link to query the Departments model
var deps = from d in conn.Departments
select d;
//append the current direction to the sort column
String sort = Session["SortColumn"].ToString() + " " + Session["SortDirection"].ToString();
grdDepartments.DataSource = deps.AsQueryable().OrderBy(sort).ToList();
grdDepartments.DataBind();
}
}
protected void grdDepCourses_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//get the selected Course id
Int32 CourseID = Convert.ToInt32(grdDepCourses.DataKeys[e.RowIndex].Values["CourseID"]);
using (DefaultConnection conn = new DefaultConnection())
{
Course objC = (from c in conn.Courses
where c.CourseID == CourseID
select c).FirstOrDefault();
conn.Courses.Remove(objC);
conn.SaveChanges();
GetDepartment();
}
}
protected void GetCourse()
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//get the course id
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
//get student info
var c = (from crs in conn.Courses
where crs.CourseID == CourseID
select crs).FirstOrDefault();
//populate the form
txtTitle.Text = c.Title;
txtCredits.Text = c.Credits.ToString();
ddlDepartment.SelectedValue = c.DepartmentID.ToString();
}
}
protected void grdDepartments_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//get the selected department id
Int32 DepartmentID = Convert.ToInt32(grdDepartments.DataKeys[e.RowIndex].Values["DepartmentID"]);
var d = (from dep in conn.Departments
where dep.DepartmentID == DepartmentID
select dep).FirstOrDefault();
//delete
conn.Departments.Remove(d);
conn.SaveChanges();
//update the grid
GetDepartments();
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//get the selected department id
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[e.RowIndex].Values["StudentID"]);
var s = (from stu in conn.Students
where stu.StudentID == StudentID
select stu).FirstOrDefault();
//delete
conn.Students.Remove(s);
conn.SaveChanges();
//update the grid
GetStudents();
}
}
protected void btnAdd_Click(object sender, EventArgs e)
{
using (DefaultConnection conn = new DefaultConnection())
{
Int32 StudentID = Convert.ToInt32(ddlStudent.SelectedValue);
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
Enrollment objE = new Enrollment();
objE.StudentID = StudentID;
objE.CourseID = CourseID;
conn.Enrollments.Add(objE);
conn.SaveChanges();
//refresh
GetStudents();
}
}
protected void ddlDepartment_SelectedIndexChanged(object sender, EventArgs e)
{
using (DefaultConnection conn = new DefaultConnection())
{
//store selected department id
Int32 DepartmentID = Convert.ToInt32(ddlDepartment.SelectedValue);
var objC = from c in conn.Courses
where c.DepartmentID == DepartmentID
orderby Title
select c;
//bind to the course dropdown
ddlCourse.DataSource = objC.ToList();
ddlCourse.DataBind();
//add default options to the 2 dropdowns
ListItem newItem = new ListItem("-Select-", "0");
ddlCourse.Items.Insert(0, newItem);
}
}
protected void GetDepartments()
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//get the student id
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
//get student info
var d = (from dep in conn.Departments
orderby dep.Name
select dep);
//populate the form
ddlDepartment.DataSource = d.ToList();
ddlDepartment.DataBind();
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//get the selected enrollment id
Int32 EnrollmentID = Convert.ToInt32(grdStudents.DataKeys[e.RowIndex].Values["EnrollmentID"]);
using (DefaultConnection conn = new DefaultConnection())
{
Enrollment objE = (from en in conn.Enrollments
where en.EnrollmentID == EnrollmentID
select en).FirstOrDefault();
conn.Enrollments.Remove(objE);
conn.SaveChanges();
GetStudents();
}
}
protected void GetStudents()
{
using (DefaultConnection conn = new DefaultConnection())
{
//Get courseID
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
//fill students grid
var stu = (from s in conn.Students
join en in conn.Enrollments on s.StudentID equals en.StudentID
where en.CourseID == CourseID
orderby s.LastName
select new { en.EnrollmentID, s.FirstMidName, s.LastName, s.StudentID, s.EnrollmentDate }).Distinct();
//populate the form
grdStudents.DataSource = stu.ToList();
grdStudents.DataBind();
//fill students dropdown
var allstu = (from s in conn.Students
join en in conn.Enrollments on s.StudentID equals en.StudentID
orderby s.LastName
select new { en.EnrollmentID, s.FirstMidName, s.LastName, s.StudentID, s.EnrollmentDate, DisplayField = (s.LastName + ", " + s.FirstMidName) }).Distinct();
ddlStudent.DataTextField = "DisplayField";
//populate the form
ddlStudent.DataSource = allstu.ToList();
ddlStudent.DataBind();
//add default options to the dropdown
ListItem newItem = new ListItem("-Select-", "0");
ddlStudent.Items.Insert(0, newItem);
pnlStudents.Visible = true;
}
}
protected void GetStudents()
{
//connect
using (DefaultConnection conn = new DefaultConnection())
{
//get the student id
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//get student info
var s = (from stu in conn.Students
where stu.StudentID == StudentID
select stu).FirstOrDefault();
if (s != null)
{
//populate the form
txtFirstName.Text = s.FirstMidName;
txtLastName.Text = s.LastName;
txtEnrollDate.Text = s.EnrollmentDate.ToString("yyyy-MM-dd");
}
var objE = (from en in conn.Enrollments
join c in conn.Courses on en.CourseID equals c.CourseID
join d in conn.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();
ddlDepartment.ClearSelection();
ddlCourse.ClearSelection();
//fill departments dropdown
var deps = (from dep in conn.Departments
orderby dep.Name
select dep);
//populate the form
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;
}
}
