protected void grdDepartments_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
// function delete department from gridview
// determine the row the user clicked
Int32 gridIndex = e.RowIndex;
// find department id in selected row
Int32 DepartmentID = Convert.ToInt32(grdDepartments.DataKeys[gridIndex].Value);
// connect to database
var conn = new ContosoEntities();
// delete the selected department
/* var objDep = (from d in conn.Departments
* where d.DepartmentID == DepartmentID
* select d).First(); */
Department d = new Department();
d.DepartmentID = DepartmentID;
conn.Departments.Attach(d);
conn.Departments.Remove(d);
conn.SaveChanges();
// refresh the gridview
getDepartments();
}
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack == false)
{
// check the url for an ID
if (!String.IsNullOrEmpty(Request.QueryString["StudentID"]))
{
// get the ID from the url
Int32 StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
// connect to the database
var conn = new ContosoEntities();
// find the selected student
var objStudent = (from s in conn.Students
where s.StudentID == StudentID
select s).FirstOrDefault();
// populate the form
txtLastName.Text = objStudent.LastName;
txtFirstName.Text = objStudent.FirstMidName;
txtEnrollmentDate.Text = objStudent.EnrollmentDate.ToString();
}
}
}
protected void getDepartments()
{
// connect to database
var conn = new ContosoEntities();
// run the query using LINQ
var Departments = from d in conn.Departments
select d;
// display query result in grideview
grdDepartments.DataSource = Departments.ToList();
grdDepartments.DataBind();
}
protected void getStudents()
{
// connect to database
var conn = new ContosoEntities();
// run the query using LINQ
var Students = from s in conn.Students
select s;
// display query result in grideview
grdStudents.DataSource = Students.ToList();
grdStudents.DataBind();
}
protected void btnSave_Click(object sender, EventArgs e)
{
// check if we are adding a student or editing one
Int32 StudentID = 0;
if (!String.IsNullOrEmpty(Request.QueryString["StudentID"]))
{
StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
}
// connect
var conn = new ContosoEntities();
// use the student class to create a new student object
Student s = new Student();
// fill the properties of the new department object
s.LastName = txtLastName.Text;
s.FirstMidName = txtFirstName.Text;
s.EnrollmentDate = Convert.ToDateTime(txtEnrollmentDate.Text);
// save the new object to the database
if (StudentID == 0)
{
conn.Students.Add(s);
}
else
{
s.StudentID = StudentID;
conn.Students.Attach(s);
conn.Entry(s).State = System.Data.Entity.EntityState.Modified;
}
conn.SaveChanges();
// redirect to the departments page
Response.Redirect("students.aspx");
}
protected void btnSave_Click(object sender, EventArgs e)
{
// check if we are adding of editing
Int32 DepartmentID = 0;
if (!String.IsNullOrEmpty(Request.QueryString["DepartmentID"]))
{
DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
}
// connect
var conn = new ContosoEntities();
// use the department class to create a new department object
Department d = new Department();
// fill the properties of the new department object
d.Name = txtName.Text;
d.Budget = Convert.ToDecimal(txtBudget.Text);
// save the object to the database
if (DepartmentID == 0)
{
conn.Departments.Add(d);
}
else
{
d.DepartmentID = DepartmentID;
conn.Departments.Attach(d);
conn.Entry(d).State = System.Data.Entity.EntityState.Modified;
}
conn.SaveChanges();
// redirect to the departments page
Response.Redirect("departments.aspx");
}
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack == false)
{
// check the url for an ID
if (!String.IsNullOrEmpty(Request.QueryString["DepartmentID"]))
{
// get Id from the url
Int32 DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
// connect to the database
var conn = new ContosoEntities();
// find selected department
var objDep = (from d in conn.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
// populate the form
txtName.Text = objDep.Name;
txtBudget.Text = objDep.Budget.ToString();
}
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
// create a function to delete student from gridview
// determine the row the user clicked
Int32 gridIndex = e.RowIndex;
// find student ID in selected row
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[gridIndex].Value);
// connect to database
var conn = new ContosoEntities();
// delete the selected student
Student s = new Student();
s.StudentID = StudentID;
conn.Students.Attach(s);
conn.Students.Remove(s);
conn.SaveChanges();
// refresh the gridview
getStudents();
}
