Entity Framework Foreign Key Inserts with Auto-Id
I think it is necessary to configure your one-to-one relationship explicitely using Fluent API:
public class MyContext : DbContext
{
// ... your DbSets
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<User>()
.HasRequired(u => u.user_profile)
.WithRequiredPrincipal();
}
}
And the entity classes:
public class User
{
[Key]
public int user_id {get;set;}
public string username {get;set;}
public string email {get;set;}
public virtual User_Profile user_profile {get;set;}
}
public class User_Profile
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int user_id {get;set;}
public string firstname {get;set;}
public string lastname {get;set;}
}
It's necessary to switch off DatabaseGeneratedOption
from Identity
to None
in one of the classes. I have swapped principal and dependent as it seems that the User
should be the principal. The [ForeignKey(...)]
is not necessary because EF will recognize user_id
in User_Profile
as a FK property to User
.
A code like this...
using (var context = new MyContext())
{
var user = new User();
var userProfile = new User_Profile();
user.user_profile = userProfile;
context.Users.Add(user);
context.SaveChanges();
}
...should work then as you expect and save both related entities to the database.
chrisg229
Updated on June 20, 2022Comments
-
chrisg229 almost 2 years
I have 2 Entities User and User_Profile (one to one relationship). I have linked them as follows:
public class User { [Key] [ForeignKey("user_profile")] public int user_id {get;set;} public string username {get;set;} public string email {get;set;} public virtual User_Proile user_profile {get;set;} } public class User_Profile { [Key] public int user_id {get;set;} public string firstname {get;set;} public string lastname {get;set;} }
user_id is a PK in both SQL Server's User and User_Profile tables. It is also set as an Identity column in the User table.
When I try to insert a new record via the EFDBContext Add/SaveChanges. I get the following error: "user_id cannot be NULL in the User_Profile table" This makes perfect sense as this is a PK column. I was hoping EF would be able to take the Identity user_id from Users and Insert it into User_Profile user_id when saving.
Is this possible and if so how would I implement that?
UPDATE: Please note that I manually created the DB tables and code classes so I dont have access to StoreGeneratedPattern via the .edmx file.
-
chrisg229 over 12 yearsI just did a search and there is no .edmx file in my app directory. I am using EF4. Am I missing something?
-
Saad Imran. over 12 yearsUmm, it should be there. The .edmx file is basically the model you generated, so look for a file with that name. Or you can just right click the model in your solution explorer and open it with the xml editor.
-
chrisg229 over 12 yearsI cant find any .edmx file and the closest thing I have to a model are the class.cs files I created. Please note that I did manually create the DB table and classes (making the property/column names the same), then I just instantiated the DBContext and make the proper connection in the web.config. Everything seem to work great ...except the identity issue above.
-
Saad Imran. over 12 yearsAhh I thought you at least used designer to generate the mappings. Unfortunately I don't know of any other way. If you can't seem to figure it out, that's always an option. Generate a model, import your tables and turn off code generation so you can still use your entity/context classes.
-
chrisg229 over 12 yearsI guess I might have to resort to that. Thanks for your help Saad!
-
chrisg229 over 12 yearsWow! That worked EXACTLY as you said it would. Many Thanks Slauma!