Stored procedure:
    
    CREATE PROCEDURE [dbo].[getCustomer]
    
    AS
    
    BEGIN
    
        SELECT TOP 10
    
            CustomerID, CustomerName, City
    
        FROM
    
            Customers
    
    END
    
    ---------------------------------------
    
    CREATE PROCEDURE [dbo].[getOrder]
    
    @CustomerID nchar(5)
    
    AS
    
        SELECT
    
            OrderID,
    
            OrderDate,
    
            RequiredDate,
    
            ShippedDate
    
        FROM
    
            Orders
    
        WHERE
    
            CustomerID = @CustomerID
    
        ORDER BY
    
            OrderID
    
    ------------------------------------------------
    
    Controller Code：
    
    using (IDbConnection conn = new SqlConnection(@"xxx))
    
                {
    
                    List<CustomerModel> result = new List<CustomerModel>();
    
                    var customers = conn.Query<Customer>("getCustomer",commandType: CommandType.StoredProcedure);
    
                    foreach (Customer customer in customers.ToList())
    
                    {
    
                        DynamicParameters paramView = new DynamicParameters();
    
                        paramView.Add("@CustomerID", customer.CustomerId, DbType.Int32, ParameterDirection.Input);
    
                        var orders = conn.Query<Order>("getOrder",paramView,commandType: CommandType.StoredProcedure);
    
                        result.Add(new CustomerModel { Customer=customer, Orders=orders.ToList() });
    
                    }
    
                    //result.Customers
    
                    return View(result);
    
                }
    
    -----------------------------------------------------
    
    View Code:
    
    @{
    
        WebGrid webGrid = new WebGrid(source: Model, canSort: false, canPage: false);
    
    }
    
    @webGrid.GetHtml(
    
                htmlAttributes: new { @id = "WebGrid", @class = "Grid" },
    
                columns: webGrid.Columns(
    
                    webGrid.Column(null, null, format: @<text><img src="~/Images/plus.png" /><div style="display:none"></div></text>),
    
                    webGrid.Column("Customer.CustomerName", "Customer Name"),
    
                    webGrid.Column("Customer.City", "City"),
    
                    webGrid.Column(format: (item) =>
    
                    {
    
                        WebGrid childGrid = new WebGrid(source: item.Orders, canSort: false, canPage: false);
    
                        return childGrid.GetHtml(
    
                            htmlAttributes: new { @class = "ChildGrid" },
    
                            columns: childGrid.Columns(
    
                                    childGrid.Column("OrderId", "OrderId"),
    
                                    childGrid.Column("OrderDate", "OrderDate"),
    
                                    childGrid.Column("RequiredDate", "RequiredDate"),
    
                                    childGrid.Column("ShippedDate", "ShippedDate")
    
                                    )
    
                       );
    
                    })
    
                 )
    
        );