Entity Framework 6 to add one-to-one association between a SalesOrder.CustomerID and Customer.Id - entity-framework

Question

To everyone,
I'm trying to instantiate a SalesOrder Customer object so I can add the Customer's DisplayName to the SalesOrder.
I have this code in the SalesOrder class:
using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
#nullable disable
namespace DataLayer
{
public partial class SalesOrder
{
public SalesOrder()
{
this.SalesOrderLineItems = new HashSet<SalesOrderLineItem>();
//this.Customer = new Customer().;
}
public Guid Id { get; set; }
public DateTime Date { get; set; }
public Guid CustomerID { get; set; }
public virtual ICollection<SalesOrderLineItem> SalesOrderLineItems { get; set; }
public virtual Customer Customer { get; set; }
}
}
The SalesOrder does retrieve the SalesOrderLineItems. However, everything I try to fill the instance of the Customer fails. I have the CustomerID FK on the SalesOrder object. I'm trying to use that PK/FK reference to the Customer row to bring in the instance of the customer which will allow me to reach the cust.DisplayName property. Just as I have with the SalesOrder.SalesOrderLineItems I want the Customer object to be properly attached to the SalesOrder object.
Here is the table structure which is normal PK/FK configuration between SalesOrder.CustomerID FK and Customer.Id PK.
Here is the code in the API controller that loads the SalesOrderLineItems to the SalesOrder object. This is all working perfectly...I think.
public JsonResult GetSalesOrderByID(Guid salesorderid)
{
{
var context = db.Set<SalesOrder>();
SalesOrder sorder = context.First(s => s.Id == salesorderid);
context.Entry(sorder).Collection(l => l.SalesOrderLineItems).Load();
return new JsonResult(sorder);
}
}
USE [Backend]
GO
/****** Object: Table [dbo].[**SalesOrder**] Script Date: 12/16/2022 9:20:54 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[SalesOrder](
[ID] [uniqueidentifier] ROWGUIDCOL NOT NULL,
[Date] [datetime] NOT NULL,
[CustomerID] [uniqueidentifier] NOT NULL,
CONSTRAINT [PK_SalesOrder] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[SalesOrder] ADD CONSTRAINT [DF_SalesOrder_ID] DEFAULT (newid()) FOR [ID]
GO
ALTER TABLE [dbo].[SalesOrder] WITH CHECK ADD CONSTRAINT [FK_SalesOrder_Customer] FOREIGN KEY([CustomerID])
REFERENCES [dbo].[Customer] ([ID])
GO
ALTER TABLE [dbo].[SalesOrder] CHECK CONSTRAINT [FK_SalesOrder_Customer]
GO
USE [Backend]
GO
/****** Object: Table [dbo].[Customer] Script Date: 12/16/2022 9:29:17 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Customer](
[ID] [uniqueidentifier] ROWGUIDCOL NOT NULL,
[DisplayName] [nvarchar](max) NOT NULL,
[FirstName] [nvarchar](50) NOT NULL,
[LastName] [nvarchar](50) NOT NULL,
CONSTRAINT [PK_Customer] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
ALTER TABLE [dbo].[Customer] ADD CONSTRAINT [DF_Customer_ID] DEFAULT (newid()) FOR [ID]
GO
Here is the JSON response as of now:
{
"id": "fea1996f-7569-4556-971c-ecb125a53b53",
"date": "2022-10-30T00:00:00",
"customerID": "23a85521-d834-47b9-be0a-2d34fde6c2dc",
"salesOrderLineItems": [
{
"id": "7ca18a2d-1c3c-4ab6-a583-aafe3342f3d2",
"salesOrderID": "fea1996f-7569-4556-971c-ecb125a53b53",
"productID": "a8ee410e-aba3-45dc-aec3-5be389d98f96",
"productDisplayName": "Acme Soap",
"quantity": 30,
"price": 200
},
{
"id": "286997cc-b552-44fd-b7dc-fb60cfe88b61",
"salesOrderID": "fea1996f-7569-4556-971c-ecb125a53b53",
"productID": "0c56a53a-25c2-4ebf-a859-591edefb2657",
"productDisplayName": "Central Widget",
"quantity": 200,
"price": 1.05
}
],
"customer": null
}
The ideal response would be:
{
"id": "fea1996f-7569-4556-971c-ecb125a53b53",
"date": "2022-10-30T00:00:00",
"customerID": "23a85521-d834-47b9-be0a-2d34fde6c2dc",
"CustomerDisplayName": "Jack Doe",
"salesOrderLineItems": [
{
"id": "7ca18a2d-1c3c-4ab6-a583-aafe3342f3d2",
"salesOrderID": "fea1996f-7569-4556-971c-ecb125a53b53",
"productID": "a8ee410e-aba3-45dc-aec3-5be389d98f96",
"productDisplayName": "Acme Soap",
"quantity": 30,
"price": 200
},
{
"id": "286997cc-b552-44fd-b7dc-fb60cfe88b61",
"salesOrderID": "fea1996f-7569-4556-971c-ecb125a53b53",
"productID": "0c56a53a-25c2-4ebf-a859-591edefb2657",
"productDisplayName": "Central Widget",
"quantity": 200,
"price": 1.05
}
]
}
I'm trying to populate the full customer object to start with but that might not be necessary.
Ideally I'd just like the Customer.Display name to be added as a property of the SalesOrder. Then I wouldn't need the entire Customer object which is not necessary.
So maybe SalesOrder looks like this with just the CustomerDisplayName added. But I still need to reach the related Customer to derive the CustomerDisplayName.
namespace DataLayer
{
public partial class SalesOrder
{
public SalesOrder()
{
this.SalesOrderLineItems = new HashSet<SalesOrderLineItem>();
//this.Customer = new Customer().;
}
public Guid Id { get; set; }
public DateTime Date { get; set; }
public Guid CustomerID { get; set; }
public virtual ICollection<SalesOrderLineItem> SalesOrderLineItems { get; set; }
public virtual string CustomerDisplayName { get; set; }
}
}
Thanks for all your help in advance,
E
I tried to decorate the SalesOrder with the
[ForeignKey] attribute and define the CustomerID, but that didn't work.
I tried to load the Customer collection as I did with the SalesOrderLineItems, but of course the Customer doesn't have the SalesOrder relationship as the SalesOrderLineItem does. The Customer stands alone by itself and is referenced/associated in SalesOrder as a FK.