Insert Update Delete Linq

Employee Name:
Address:
Date of Birth:	(eg. MM/dd/yyyy)
Joing Date:	(eg. MM/dd/yyyy)
CompanyName:

//-----Code

SqlConnection CN = new SqlConnection(ConfigurationManager.ConnectionStrings["EmployeeConnectionString"].ConnectionString);
DataClassesDataContext db = new DataClassesDataContext();
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
BindData();
ddlBindlist();
ViewState["sortOrder"] = "";
bindGridView("", "");
}
}

private void BindData()
{
try
{
GridView1.DataSource = from emp in db.Employees
join cinfo in db.CompanyInformations on emp.CompanyId equals cinfo.Id
orderby emp.Id
select new { emp.Id, emp.Name, emp.Address, emp.DateOfBirth, emp.JoingDate, cinfo.CompanyName };
GridView1.DataBind();
}
catch (Exception ex)
{
throw ex;
}
}

protected void btnAdd_Click(object sender, EventArgs e)
{
if (btnAdd.Text == "Add")
{
Employees emp = new Employees();
emp.Name = txtEmpName.Text;
emp.Address = txtAddress.Text;
emp.DateOfBirth = txtDoB.Text;
emp.JoingDate = txtJoingDate.Text;
emp.CompanyId = Convert.ToInt32(ddlCompanyid.SelectedValue);

db.Employees.InsertOnSubmit(emp);
try
{
db.SubmitChanges();
}
catch (Exception ex)
{
throw ex;
}
finally
{
lblMessage.Text = "Inserted Successfully";
}
}
else if (btnAdd.Text == "Update")
{
Employees emp = db.Employees.Single(ep => ep.Id == Convert.ToInt32(GridView1.SelectedRow.Cells[2].Text));
emp.Name = txtEmpName.Text;
emp.Address = txtAddress.Text;
emp.DateOfBirth = txtDoB.Text;
emp.JoingDate = txtJoingDate.Text;
emp.CompanyId = Convert.ToInt32(ddlCompanyid.SelectedValue);

try
{
db.SubmitChanges();
}
catch (Exception ex)
{
throw ex;
}
finally
{
lblMessage.Text = "Updated Successfully";
}
}

clear();
btnAdd.Text = "Add";
BindData();
}

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
txtEmpName.Text = GridView1.SelectedRow.Cells[3].Text;
txtAddress.Text = GridView1.SelectedRow.Cells[4].Text;
txtDoB.Text = GridView1.SelectedRow.Cells[5].Text;
txtJoingDate.Text = GridView1.SelectedRow.Cells[6].Text;
ddlCompanyid.SelectedItem.Text = GridView1.SelectedRow.Cells[7].Text;
btnAdd.Text = "Update";
}

private void clear()
{
txtEmpName.Text = "";
txtAddress.Text = "";
txtDoB.Text = "";
txtJoingDate.Text = "";
}

protected void btnCancle_Click1(object sender, EventArgs e)
{
clear();
}

public void ddlBindlist()
{
try
{
//DataClassesDataContext db = new DataClassesDataContext();
ddlCompanyid.DataSource = from cinfo in db.CompanyInformations
select cinfo;
ddlCompanyid.DataTextField = "CompanyName";
ddlCompanyid.DataValueField = "Id";
ddlCompanyid.DataBind();
}
catch (Exception ex)
{
throw ex;
lblMessage.Text = ex.Message;
}
}
protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//int Id = Convert.ToInt32(GridView1.SelectedRow.Cells[2].Text);
int Id = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Value);
DeleteRecordByID(Id);
lblMessage.Text = "Record deleted";
}

protected void DeleteRecordByID(long Id)
{
//DataClassesDataContext db = new DataClassesDataContext();
Employees toDelete = db.Employees.Single(p => p.Id == Id);
db.Employees.DeleteOnSubmit(toDelete);
db.SubmitChanges();
BindData();
lblMessage.Text = "Record deleted";
}
protected void GridView1_RowDeleted(object sender, GridViewDeletedEventArgs e)
{
if (e.Exception == null)
{
lblMessage.Text = "Record deleted";
}

else
{
lblMessage.Text = e.Exception.Message;
e.ExceptionHandled = true;
}
}

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
BindData();
}

public void bindGridView(string sortExp, string sortDir)
{
if (CN.State == ConnectionState.Closed)
{
CN.Open();
}

var company = db.SpCompanyInformation();
//SqlCommand mySqlCommand = new SqlCommand("select Employee.Id, Employee.Name, Employee.Address, Employee.DateOfBirth, Employee.JoingDate, CompanyInformation.CompanyName from Employee left join CompanyInformation on Employee.CompanyId = CompanyInformation.Id", CN);
SqlDataAdapter mySqlAdapter = new SqlDataAdapter(mySqlCommand);
DataSet myDataSet = company;
mySqlAdapter.Fill(myDataSet);

DataView myDataView = new DataView();
myDataView = myDataSet.Tables[0].DefaultView;

if (sortExp != string.Empty)
{
myDataView.Sort = string.Format("{0} {1}", sortExp, sortDir);
}

GridView1.DataSource = myDataView;
GridView1.DataBind();

if (CN.State == ConnectionState.Open)
{
CN.Close();
}
}
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
bindGridView(e.SortExpression, sortOrder);
}
public string sortOrder
{
get
{
if (ViewState["sortOrder"].ToString() == "desc")
{
ViewState["sortOrder"] = "asc";
}
else
{
ViewState["sortOrder"] = "desc";
}

return ViewState["sortOrder"].ToString();
}
set
{
ViewState["sortOrder"] = value;
}
}