1.备份

        SqlConnection connection = new SqlConnection(ConfigurationManager.AppSettings["Connection"]);
        string dbFileName = DateTime.Now.ToString("yyyyMMddHHmmss")+".bak";
        try
        {
            SqlCommand command = new SqlCommand("use master;backup database xxdl to disk=@path;", connection);
            connection.Open();
            string path = Server.MapPath("~\\App_Data") + "\\" + dbFileName;
            command.Parameters.AddWithValue("@path", path);
            command.ExecuteNonQuery();
            lblBackup.Text = "数据库备份成功";
        }
        catch (Exception ex)
        {

            lblBackup.Text = ex.Message;
        }
        finally
        {
            connection.Close();
        }
       
        Bind();//产生了新备份文件，更新下拉框

2 还原

        SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["Connection"]);
        string dbFileName = ddlRestore.SelectedValue;
        if (dbFileName == string.Empty)
        {
            lblRestore.Text = "没有数据库备份文件，请先备份";
            return;
        }
        try
        {
         string sql2 = "Alter Database xxdl Set Offline with Rollback immediate;use master;restore database xxdl  from disk=@path With Replace;Alter Database xxdl  Set OnLine With rollback Immediate;";
         SqlCommand command = new SqlCommand(sql2,conn);
         conn.Open();
         string path = Server.MapPath("~\\App_Data") + "\\" + dbFileName;
         command.Parameters.AddWithValue("@path", path);
         command.ExecuteNonQuery();
            lblRestore.Text = "数据库还原成功";
        }
        catch (System.Exception ex)
        {
            lblRestore.Text = ex.Message;
        }
        finally
        {
            conn.Close();
            Session.Abandon();
            Response.Redirect("login.aspx");
        }