ASP.net将多个表条目添加到数据库

Question

我正在使用Visual Studio 2015和Entity Framework 6.我正在尝试将输入信息中的条目添加到多个表中。

这是我到目前为止所做的：

 protected void btnOrder_Click(object sender, EventArgs e)
    {

        using (FlowerCompanyEntities flower = new FlowerCompanyEntities())
        {
         int rFlowers = 0;
            Boolean rVase = false;
            DateTime DeliveryDate = DateTime.Parse(tbDelivery.Text);
            string flowerArrangement = ddlListFlowers.SelectedValue;

            if (flowerArrangement == "f2")
            {
                rFlowers = 1;
            }
            if (flowerArrangement == "f3")
            {
                rFlowers = 2;
            }
            if (flowerArrangement == "f1")
            {
                rFlowers = 3;
            }
            if (flowerArrangement == "f4")
            {
                rFlowers = 4;
            }
            if (flowerArrangement == "f5")
            {
                rFlowers = 5;
            }

            string vase = rbList.SelectedItem.Value.ToString();


            if (vase == "NO")
            {
                rVase = false;
            }
            if (vase == "YES")
            {
                rVase = true;
            }



            Customers cust = new Customers();
            Addresses Addr = new Addresses();
            Phone Pho = new Phone();
            Delivery Del = new Delivery();
            Arrangements arr = new Arrangements();
            OrderStatus ordstat = new OrderStatus();
            Orders ord = new Orders();

            Pho.Phone1 = tbPhone.Text;
            Addr.Street = tbStreet.Text;
           Addr.City = tbCity.Text;
            Addr.States = tbState.Text;
            Addr.Zip = tbZip.Text;
            cust.FirstName = tbFirstName.Text;
            cust.LastName = tbLastName.Text;
             Del.DeliverDate = DeliveryDate;
           arr.FlowerID = rFlowers;
           ordstat.OrderStatus1 = tbStatus.Text;
            ord.Vase = rVase;
            ord.OrderMessage = tbOrderMessage.Text;




            try {
                flower.Phone.Add(Pho);

                flower.Addresses.Add(Addr);

                flower.Customers.Add(cust);

                flower.Delivery.Add(Del);

                flower.Arrangements.Add(arr);

                flower.OrderStatus.Add(ordstat);

                flower.Orders.Add(ord);

                flower.SaveChanges();
                Response.Redirect("Orders.aspx");
            }

            catch { }

        }

但是，在按钮上单击我会收到异常错误。我还意识到其中一些表 - 包含这些表将需要放入其他表的外键。

问题：当有多个表和外键时，如何将所有这些条目添加到我的数据库？