protected void GetStudent()
{
try
{
//look up selected student and fill form
using (DefaultConnection db = new DefaultConnection())
{
//store id from the url in a variable
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//look up student
Student stud = (from s in db.Students
where s.StudentID == StudentID
select s).FirstOrDefault();
//populate form fields
txtLast.Text = stud.LastName;
txtFirst.Text = stud.FirstMidName;
txtEnroll.Text = stud.EnrollmentDate.ToString();
//populate all courses student is enrolled in
var objK = (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 = objK.ToList();
grdCourses.DataBind();
}
}
catch (Exception e)
{
Response.Redirect("error.aspx");
}
}
protected void GetDepartment()
{
try
{
//look up the selected department and fill the form
using (DefaultConnection db = new DefaultConnection())
{
//store the id from the url in a variable
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
//look up the department
Department dep = (from d in db.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
//pre-populate the form fields
txtName.Text = dep.Name;
txtBudget.Text = dep.Budget.ToString();
}
}
catch (Exception e)
{
Response.Redirect("error.aspx");
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
try
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//create new course and fill properties
Course objC = new Course();
objC.Title = txtTitle.Text;
objC.Credits = Convert.ToInt32(txtCredits.Text);
objC.DepartmentID = Convert.ToInt32(ddlDepartment.SelectedValue);
//save
db.Courses.Add(objC);
db.SaveChanges();
//redirect
Response.Redirect("courses.aspx");
}
}
catch (Exception ex)
{
Response.Redirect("error.aspx");
}
}
protected void GetStudents()
{
try
{
//use entity framework to connect and get list of Departments
using (DefaultConnection db = new DefaultConnection())
{
var stud = from d in db.Students
select d;
//bind the stud query result to grid
grdStudents.DataSource = stud.ToList();
grdStudents.DataBind();
}
}
catch (NullReferenceException e)
{
Trace.Write("An error occured during operation with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
catch (Exception e)
{
Trace.Write("Database unavailable with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
using (DefaultConnection db = new DefaultConnection())
{
Instructor objI = new Instructor();
objI.FirstName = txtFirstName.Text;
objI.LastName = txtLastName.Text;
objI.Username = txtUsername.Text;
objI.DepartmentID = Convert.ToInt32(ddlDepartment.SelectedValue);
String password = txtPassword.Text;
String salt = CreateSalt(8);
String pass_and_salt = password + salt;
// Create a new instance of the hash crypto service provider.
HashAlgorithm hashAlg = new SHA256CryptoServiceProvider();
// Convert the data to hash to an array of Bytes.
byte[] bytValue = System.Text.Encoding.UTF8.GetBytes(pass_and_salt);
// Compute the Hash. This returns an array of Bytes.
byte[] bytHash = hashAlg.ComputeHash(bytValue);
// Optionally, represent the hash value as a base64-encoded string,
// For example, if you need to display the value or transmit it over a network.
string base64 = Convert.ToBase64String(bytHash);
objI.Password = base64;
objI.Salt = salt;
db.Instructors.Add(objI);
db.SaveChanges();
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
try
{
//identify id of student to delete from the row the user has chosen
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[e.RowIndex].Values["StudentID"]);
//connect
using (DefaultConnection db = new DefaultConnection())
{
Student stud = (from s in db.Students
where s.StudentID == StudentID
select s).FirstOrDefault();
//delete
db.Students.Remove(stud);
db.SaveChanges();
//refresh grid
Response.Redirect("students.aspx");
}
}
catch (Exception ex)
{
Response.Redirect("error.aspx");
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//create new department in memory
Department dep = new Department();
//check url
if (!String.IsNullOrEmpty(Request.QueryString["DepartmentID"]))
{
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
dep = (from d in db.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
}
//fill new properties of the new department
dep.Name = txtName.Text;
dep.Budget = Convert.ToDecimal(txtBudget.Text);
//save the new department
if (String.IsNullOrEmpty(Request.QueryString["DepartmentID"]))
{
db.Departments.Add(dep);
}
db.Departments.Add(dep);
db.SaveChanges();
//redirect to department list page
Response.Redirect("departments.aspx");
}
}
protected void GetDepartment()
{
try
{
//look up the selected department and fill the form
using (DefaultConnection db = new DefaultConnection())
{
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
//look up department
Department dep = (from d in db.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
//pre-populate the form fields
txtName.Text = dep.Name;
txtBudget.Text = dep.Budget.ToString();
}
}
catch (NullReferenceException e)
{
Trace.Write("An error occured during operation with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
catch (Exception e)
{
Trace.Write("Database unavailable with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
}
protected void GetCourses()
{
try
{
using (DefaultConnection db = new DefaultConnection())
{
var cours = from d in db.Courses
select d;
//bind the cours query result to our grid
grdCourses.DataSource = cours.ToList();
grdCourses.DataBind();
}
}
catch (NullReferenceException e)
{
Trace.Write("An error occured during operation with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
catch (Exception e)
{
Trace.Write("Database unavailable with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
}
protected void GetDepartments()
{
try
{
//use entity framework to connect and get the list of departments
using (DefaultConnection db = new DefaultConnection())
{
//old query that show all department
//var deps = from d in db.Departments
// select d;
//new query filtered for logged in user only
Int32 DepartmentID = Convert.ToInt32(Session["DepartmentID"]);
var deps = from d in db.Departments
where d.DepartmentID == DepartmentID
select d;
//bind the deps query result to our grid
grdDepartments.DataSource = deps.ToList();
grdDepartments.DataBind();
}
}
catch (NullReferenceException e)
{
Trace.Write("An error occured during operation with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
catch (Exception e)
{
Trace.Write("Database unavailable with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
}
protected void btnLogin_Click(object sender, EventArgs e)
{
using (DefaultConnection db = new DefaultConnection())
{
//create instructor name
Instructor objI = new Instructor();
//first get salt value
String username = txtUsername.Text;
objI = (from i in db.Instructors
where i.Username == username
select i).FirstOrDefault();
//did we find the username
if (objI != null)
{
String salt = objI.Salt;
String password = txtPassword.Text;
String pass_and_salt = password + salt;
// Create a new instance of the hash crypto service provider.
HashAlgorithm hashAlg = new SHA256CryptoServiceProvider();
// Convert the data to hash to an array of Bytes.
byte[] bytValue = System.Text.Encoding.UTF8.GetBytes(pass_and_salt);
// Compute the Hash. This returns an array of Bytes.
byte[] bytHash = hashAlg.ComputeHash(bytValue);
// Optionally, represent the hash value as a base64-encoded string,
// For example, if you need to display the value or transmit it over a network.
string base64 = Convert.ToBase64String(bytHash);
//check if the password we just salted and hashed matches the password in db
if (objI.Password == base64)
{
//test with label
//lblError.Text = "valid login";
//store the identity in the session object
Session["InstructorID"] = objI.InstructorID;
Session["InstructorName"] = objI.FirstName + objI.LastName;
Session["DepartmentID"] = objI.DepartmentID;
//redirect to department page
Response.Redirect("departments.aspx");
}
else
{
lblError.Text = "invalid login";
}
}
else
{
lblError.Text = "Invalid login";
}
}
}
protected void GetStudent()
{
try
{
//store id from the url in a variable
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//look up selected student and fill the form
using (DefaultConnection db = new DefaultConnection())
{
//populate student instance
Student stud = (from d in db.Students
where d.StudentID == StudentID
select d).FirstOrDefault();
if (stud != null)
{
//pre-populate the form fields
txtFirstName.Text = stud.FirstMidName;
txtLastName.Text = stud.LastName;
txtEnrollDate.Text = stud.EnrollmentDate.ToString("yyyy-mm-dd");
}
//populate enrollments
var enroll = (from e in db.Enrollments
join c in db.Courses on e.CourseID equals c.CourseID
join d in db.Departments on c.DepartmentID equals d.DepartmentID
where e.StudentID == StudentID
select new { e.EnrollmentID, e.Grade, c.Title, d.Name });
grdCourses.DataSource = enroll.ToList();
grdCourses.DataBind();
//show course panel
pnlCourses.Visible = true;
}
}
catch (NullReferenceException e)
{
Trace.Write("An error occured during operation with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
catch (Exception e)
{
Trace.Write("Database unavailable with Message:", e.Message);
Trace.Write("Stack Trace", e.StackTrace);
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
try
{
using (DefaultConnection db = new DefaultConnection())
{
//create a new student in memory
Student stud = new Student();
Int32 StudentID = 0;
//check for url
if (!String.IsNullOrEmpty(Request.QueryString["StudentID"]))
{
//get id from url
StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//look up the student
stud = (from s in db.Students
where s.StudentID == StudentID
select s).FirstOrDefault();
}
//fill the properties of the new student
stud.LastName = txtLast.Text;
stud.FirstMidName = txtFirst.Text;
stud.EnrollmentDate = Convert.ToDateTime(txtEnroll.Text);
//add if we have no id in the url
if (StudentID == 0)
{
db.Students.Add(stud);
}
//save the student
db.SaveChanges();
//redirect to student list page
Response.Redirect("students.aspx");
}
}
catch (Exception ex)
{
Response.Redirect("error.aspx");
}
}
protected void GetDepartment()
{
using (DefaultConnection db = new DefaultConnection())
{
var deps = from d in db.Departments
orderby d.Name
select d;
ddlDepartment.DataSource = deps.ToList();
ddlDepartment.DataBind();
ListItem default_item = new ListItem("select", "0");
ddlDepartment.Items.Insert(0, default_item);
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
try
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//create a new department in memory
Department dep = new Department();
Int32 DepartmentID = 0;
//check for a url
if (!String.IsNullOrEmpty(Request.QueryString["DepartmentID"]))
{
//get the id from the url
DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
//look up the department
dep = (from d in db.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
}
//fill the properties of the new department
dep.Name = txtName.Text;
dep.Budget = Convert.ToDecimal(txtBudget.Text);
//add if we have no id in the url
if (DepartmentID == 0)
{
db.Departments.Add(dep);
}
//save the new department
db.SaveChanges();
//redirect to the departments list page
Response.Redirect("departments.aspx");
}
}
catch (Exception ex)
{
Response.Redirect("error.aspx");
}
}
protected void GetStudents()
{
try
{
//use enity framework to connect to get list of students
using (DefaultConnection db = new DefaultConnection())
{
var stud = from s in db.Students
select s;
//bind stud query results to our grid
grdStudents.DataSource = stud.ToList();
grdStudents.DataBind();
}
}
catch (Exception e)
{
Response.Redirect("error.aspx");
}
}
protected void grdDepartments_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//identify the departmentID to be deleted from the row user selected
Int32 DepartmentID = Convert.ToInt32(grdDepartments.DataKeys[e.RowIndex].Values["DepartmentID"]);
//connect
using (DefaultConnection db = new DefaultConnection())
{
Department dep = (from d in db.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
//delete
db.Departments.Remove(dep);
db.SaveChanges();
//refresh grid
GetDepartments();
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//identify the studentID to be deleted from the row the user selected
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[e.RowIndex].Values["StudentID"]);
//connect to database
using (DefaultConnection db = new DefaultConnection())
{
Student stud = (from d in db.Students
where d.StudentID == StudentID
select d).FirstOrDefault();
//delete
db.Students.Remove(stud);
db.SaveChanges();
//refresh grid
GetStudents();
}
}
protected void GetDepartments()
{
//use Entity Framework to connect and get the list of Departments
using (DefaultConnection db = new DefaultConnection())
{
//old query that shows all departments
//var deps = from d in db.Departments
// select d;
//new query filterd for logged in user only
Int32 DepartmentID = Convert.ToInt32(Session["DepartmentID"]);
var deps = from d in db.Departments
where d.DepartmentID == DepartmentID
select d;
//bind the deps query result to our grid
grdDepartments.DataSource = deps.ToList();
grdDepartments.DataBind();
}
}
protected void GetCourse()
{
try
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//get the selected courseid from url
Int32 CourseID = Convert.ToInt32(Request.QueryString["CourseID"]);
//query the db
Course objC = (from c in db.Courses
where c.CourseID == CourseID
select c).FirstOrDefault();
// populate the form
txtTitle.Text = objC.Title;
txtCredits.Text = objC.Credits.ToString();
ddlDepartment.SelectedValue = objC.DepartmentID.ToString();
//populate student enrollments grid
var Enrollments = from en in db.Enrollments
where en.CourseID == CourseID
orderby en.Student.LastName,
en.Student.FirstMidName
select en;
//bind to the grid
grdEnrollments.DataSource = Enrollments.ToList();
grdEnrollments.DataBind();
}
} catch (Exception e) {
//redirect
Response.Redirect("error.aspx");
}
}
protected void GetDepartments()
{
try {
//connect
using (DefaultConnection db = new DefaultConnection())
{
//get department list
var Departments = from d in db.Departments
orderby d.Name
select d;
//bind dropdown list
ddlDepartment.DataSource = Departments.ToList();
ddlDepartment.DataBind();
//add default option for dropdown after it's filled
ListItem DefaultItem = new ListItem("-Select-", "0");
ddlDepartment.Items.Insert(0, DefaultItem);
}
}
catch (Exception e)
{
Response.Redirect("error.aspx");
}
}
protected void grdCourses_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
try
{
//get selected id
Int32 EnrollmentID = Convert.ToInt32(grdCourses.DataKeys[e.RowIndex].Values["EnrollmentID"]);
//connect
using (DefaultConnection db = new DefaultConnection())
{
//get record
Enrollment objK = (from en in db.Enrollments
where en.EnrollmentID == EnrollmentID
select en).FirstOrDefault();
//delete
db.Enrollments.Remove(objK);
db.SaveChanges();
//refresh
GetStudent();
}
}
catch (Exception ex)
{
Response.Redirect("error.aspx");
}
}
