Entity Framework Core 6 自动递增非键列

Question

Entity Framework Core 6 在我的表中自动增加了不应该的列。

我在 SQL Server 中有一个表定义如下：

CREATE TABLE [dbo].[Company]
(
    [Company_ID] [int] IDENTITY(1,1) NOT NULL,
    [CompanyName] [varchar](100) NOT NULL,  
    [CreatedOnUtc] [datetime] NOT NULL,
    [AccountManager_ID] [int] NULL,
    [Project_ID] [int] NOT NULL,
    [Customer_ID] [int] NOT NULL

    CONSTRAINT [PK_Company] 
        PRIMARY KEY CLUSTERED ([Company_ID] ASC)
                    WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
                          IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, 
                          ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[Company] 
    ADD CONSTRAINT [DF_Company_CreatedOnUtc] DEFAULT (GETUTCDATE()) FOR [CreatedOnUtc]
GO

我的实体定义如下 - 我显式定义键列并且它是一个标识。

[Table("Company")]
public partial class CompanyEntity
{       
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Required]
    [DisplayName("Company ID")]
    public int Company_ID { get; set; } 
    
    [Required]
    [MaxLength(100)]
    [DisplayName("Company Name")]
    public string CompanyName { get; set; }  = "";

    [ForeignKey("AccountManager")]
    [DisplayName("Account Manager ID")]
    public int? AccountManager_ID { get; set; }                 
    
    [DatabaseGenerated(DatabaseGeneratedOption.Computed)]
    [Required]
    [DisplayName("Created On Utc")]
    public DateTime CreatedOnUtc { get; set; } 
    
    [ForeignKey("Project")]
    //[DatabaseGenerated(DatabaseGeneratedOption.None)]
    [Required]
    [DisplayName("Project ID")]
    public int Project_ID { get; set; } 
    
    [ForeignKey("Customer")]
    [Required]
    [DisplayName("Customer ID")]
    //[DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int Customer_ID { get; set; } 
    
    public AccountManagerEntity? AccountManager { get; set; } 
    public CustomerEntity Customer { get; set; } = new CustomerEntity();
    public ProjectEntity Project { get; set; } = new ProjectEntity();
}

当我创建并保存新的 CompanyEntity 记录时，

var company = new CompanyEntity() 
{
    CompanyName = "Test",
    AccountManager_ID = 1
    Project_ID = 1,
    Customer_ID = 1,
};

Context.Company.Add(company);

await Context.SaveChangesAsync();

我期望看到的情况是将新记录添加到 Company 表中，如下所示：

Company_ID: xxx (auto-incremented in DB)
CompanyName: Test
AccountManager_ID: 1
Project_ID: 1
Customer_ID: 1
CreatedOnUtc: xx/xx/xxxx (auto generated)

相反，我看到的情况是 >Project_ID 和 Customer_ID 列会自动递增。因此，我最终会得到这样的记录：

Company_ID: 1
CompanyName: Test
AccountManager_ID: 1
Project_ID: 1
Customer_ID: 1
CreatedOnUtc: 3/27/2022 18:13:00

然后，如果我删除此记录并再次运行我的代码，我最终会得到另一条记录（这是我所期望的），但 Project_ID 和 Customer_ID 已递增，而不是使用我的值：

Company_ID: 2
CompanyName: Test
AccountManager_ID: 1
Project_ID: 2
Customer_ID: 2
CreatedOnUtc: 3/27/2022 18:13:00

I可以在 SQL Server Profiler 中看到 EF 正在传递递增的值。我确信这是因为某些约定，但我已在这些列上显式设置属性。 AccountManager_ID 似乎工作正常 - 与该字段的唯一区别是它不是必填字段。我还尝试添加

[DatabaseGenerated(DatabaseGeneratedOption.None)]

到 Project_ID / Customer_ID，但这没有任何区别。

我如何告诉 EF“不要这样做”？

编辑：好的，我明白为什么会发生这种情况。因为我正在创建 CustomerEntity 和 ProjectEntity 的实例作为默认值，所以假设我也在这些其他表中创建新记录。删除 = new *Entity(); 部分解决了该问题。我添加这些只是为了让编译器在退出构造函数时发出有关具有值的不可为空属性的警告消失。哎呀。

public CustomerEntity Customer { get; set; } = new CustomerEntity();
public ProjectEntity Project { get; set; } = new ProjectEntity();

Answer 1

此代码自动创建客户和项目的新实例，并分配新的钥匙

public CustomerEntity Customer { get; set; } = new CustomerEntity();
 public ProjectEntity Project { get; set; } = new ProjectEntity();

请假

public CustomerEntity Customer { get; set; } 
 public ProjectEntity Project { get; set; }