as follows :
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
using (SqlConnection connection = new SqlConnection("server=.;uid=xxx;pwd=xxx;database=Northwind"))
{
SqlDataAdapter dataAdpater = new SqlDataAdapter("SELECT CategoryID, CategoryName,Description FROM Categories", connection);
DataSet dataSet = new DataSet();
dataAdpater.Fill(dataSet, "Categories");
if (dataSet.Tables.Contains("Categories"))
{
gvMain.DataSource = dataSet.Tables["Categories"].DefaultView;
gvMain.DataKeyNames = new string[] { "CategoryID" };
gvMain.DataBind();
}
}
}
}
protected void gvMain_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
{
using (SqlConnection connection = new SqlConnection("server=.;uid=xxx;pwd=xxx;database=Northwind"))
{
SqlDataAdapter dataAdpater = new SqlDataAdapter("SELECT * FROM Products where CategoryID=@CategoryID ", connection);
dataAdpater.SelectCommand.Parameters.Add(new SqlParameter("@CategoryID", gvMain.DataKeys[e.NewSelectedIndex].Value));
DataSet dataSet = new DataSet();
dataAdpater.Fill(dataSet, "Products");
if (dataSet.Tables.Contains("Products"))
{
gv.DataSource = dataSet.Tables["Products"].DefaultView;
gv.DataBind();
}
}
}