How add check box in gridview and save it in database

Provide more details. From where the grid is being populated and where to save? Same table or different

i have one table in that there will be a details of the products

saved by users once the user save the detail i want a gridvew with check box were admin can approved that details by checking the check box i want to save that Confirm and Pending in the same main table ..

You will have to loop and update table. Something like following example

    protected void UpdateStatus(object sender, EventArgs e)
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            string id = (row.FindControl("lblId") as Label).Text;
            bool isChecked = (row.FindControl("CheckBox1") as CheckBox).Checked;
            string status = isChecked ? "confirmed" : "pending";
            string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
            SqlCommand cmd = new SqlCommand("update myTable set Status = '" + status + "' where Id='" + id + "'");
            using (SqlConnection con = new SqlConnection(conString))
            {
                cmd.Connection = con;
                cmd.ExecuteNonQuery();
            }
        }
    }