Entity Framework Code First to Existing Database Error 6002

Question

Hello all,

I have applied Code First to an Existing Database (following this tutorial : http://msdn.microsoft.com/en-us/data/jj200620.aspx).

It created the context and all classes correctly. But it gave this message for every table in the database :

Warning 20 Error 6002: The table/view 'xx' does not have a primary key defined. The key has been inferred and the definition was created as a read-only table/view.

All tables have an Id which has Id mark checked. What should I do for this? Should I ignore this message or do something else?

Thanks.

Answer 1

http://social.msdn.microsoft.com/Forums/en-US/home?forum=adodotnetentityframework

Answer 2

You need to decorate identity columns with the Key attribute, eg:

public partial class Blog 
{ 
    public Blog() 
    { 
        Posts = new HashSet<Post>(); 
    } 

    [Key] 
    public int BlogId { get; set; } 
 
    [StringLength(200)] 
    public string Name { get; set; } 
 
    [StringLength(200)] 
    public string Url { get; set; } 
 
    public virtual ICollection<Post> Posts { get; set; } 
}

---

Hope that helps
Please don't forget to upvote posts which you like and mark those which answer your question.

Answer 3

Thank you for your response Mr. Oneill.

I have realized that [Key] was put in many property in classes.

So I guess I should remove [Key] from those which are not identities, right?

Thank you.

Answer 4

Definitely.

If you put it on all the fields then the whole lot would become a weird composite key.

---

Hope that helps
Please don't forget to upvote posts which you like and mark those which answer your question.

Answer 5

I have realized that [Key] was put in many property in classes.

So I guess I should remove [Key] from those which are not identities, right?

No not necessarily becuase there can be a primary-key that it not based on Idenity auto incremented column. The primay-key can be programmically generated and applied as the primary-key, like a GUID being used as the primary-key or other means to generate the primary-key other than using an Idenity int auto increamented column as the primary-key.

http://peterkellner.net/2012/01/15/entityframework-codefirst-and-autokey-generation/

Answer 6

Errm.....

The script for the tables is in the link above:

CREATE TABLE [dbo].[Blogs] ( 
    [BlogId] INT IDENTITY (1, 1) NOT NULL, 
    [Name] NVARCHAR (200) NULL, 
    [Url]  NVARCHAR (200) NULL, 
    CONSTRAINT [PK_dbo.Blogs] PRIMARY KEY CLUSTERED ([BlogId] ASC) 
); 
 
CREATE TABLE [dbo].[Posts] ( 
    [PostId] INT IDENTITY (1, 1) NOT NULL, 
    [Title] NVARCHAR (200) NULL, 
    [Content] NTEXT NULL, 
    [BlogId] INT NOT NULL, 
    CONSTRAINT [PK_dbo.Posts] PRIMARY KEY CLUSTERED ([PostId] ASC), 
    CONSTRAINT [FK_dbo.Posts_dbo.Blogs_BlogId] FOREIGN KEY ([BlogId]) REFERENCES [dbo].[Blogs] ([BlogId]) ON DELETE CASCADE 
);

BlogId and PostId should be marked  [Key]

---

Hope that helps
Please don't forget to upvote posts which you like and mark those which answer your question.