当IDENTITY_INSERT设置为OFF时，获取“无法在表'OrderPromo'中为标识列插入显式值”。 在桌子上没有身份

Question

I have this table created like so:

USE [OrderMore]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[OrderPromo](
    [OrderId] [int] NOT NULL,
    [PromoId] [int] NOT NULL,
    [Created] [datetime] NOT NULL,
 CONSTRAINT [PK_dbo.OrderPromo] PRIMARY KEY CLUSTERED 
(
    [OrderId] 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].[OrderPromo]  WITH CHECK ADD  CONSTRAINT [FK_dbo.OrderPromo_dbo.Order_OrderId] FOREIGN KEY([OrderId])
REFERENCES [dbo].[Order] ([OrderID])
GO
ALTER TABLE [dbo].[OrderPromo] CHECK CONSTRAINT [FK_dbo.OrderPromo_dbo.Order_OrderId]

The interesting entities look like this:

[Table("OrderPromo")]
public class OrderPromo : EntityBase
{
    /// <summary>
    /// 
    /// </summary>
    [Key, ForeignKey("Order")]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int OrderId { get; set; }

    /// <summary>
    /// 
    /// </summary>
    public int PromoId { get; set; }

    /// <summary>
    /// 
    /// </summary>
    public virtual Order Order { get; set; }

}

and:

[Table("Order")]
    public partial class Order : EntityBase
    {
        /// <summary>
        /// 
        /// </summary>
        [Key]
        public int OrderID { get; set; }

        /// <summary>
        /// 
        /// </summary>
        public virtual Transaction Transaction { get; set; }

        /// <summary>
        /// If there is an Promo used on this Order, it will be recorded in the OrderPromo table.
        /// </summary>
        public virtual OrderPromo OrderPromo { get; set; }
    }

The issue comes when I attempt to insert the data into the database. I receive the Cannot insert explicit value for identity column in table 'OrderPromo' when IDENTITY_INSERT is set to OFF.

However, there is no Identity column in the OrderPromo table. I have even tried to set IDENTITY_INSERT to ON just to be 100% sure, and SQL gives the error indicating there is no Identity column on the table.

Thank you.

EDIT--

Table definition for Order:

USE [OrderMore]
GO
/****** Object:  Table [dbo].[Order]    Script Date: 01/05/2017 10:57:19 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Order](
    [OrderID] [int] IDENTITY(1,1) NOT NULL,
    [OrderFormID] [int] NOT NULL,
    [Notes] [nvarchar](250) NULL,
    [Created] [datetime] NOT NULL,
    [TransactionID] [int] NOT NULL,
    [OrderSequenceContext] [int] NOT NULL DEFAULT ((0)),
 CONSTRAINT [PK_dbo.Order] PRIMARY KEY CLUSTERED 
(
    [OrderID] 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].[Order]  WITH CHECK ADD  CONSTRAINT [FK_dbo.Order_dbo.Transaction_TransactionID] FOREIGN KEY([TransactionID])
REFERENCES [dbo].[Transaction] ([TransactionID])
GO
ALTER TABLE [dbo].[Order] CHECK CONSTRAINT [FK_dbo.Order_dbo.Transaction_TransactionID]

Answer 1

You can try turn the IDENTITY_INSERT On like

SET IDENTITY_INSERT Order ON
--Insert script here
SET IDENTITY_INSERT Order OFF

Answer 2

You are declaring OrderId to be the primary key in table OrderPromo although it seems to be a foreign key. It should be the primary key of table Order.

Remove the primary key on OrderId from OrderPromo and it should work.

I believe what's happening is that the insert is trying to force the value of the referenced Order into the OrderId field of OrderPromo, causing it to fail.