ASP.NET MVC 3, SQL Server - sql-server

Question

First I'll show you what I do, and that there is. My project in ASP.NET MVC 3.
This is model for table Business.
[Table("Business")]
public class Business
{
[Key]
public long? BusinessId { get; set; }
public Int32 LegalTypeId { get; set; }
public Int16 BusinessTypeId { get; set; }
public Int64 OwnerId { get; set; }
public Int32 MainIndustryFieldId { get; set; }
public String NameNative { get; set; }
public String NameEnglish { get; set; }
public Byte[] Logo { get; set; }
public DateTime CreateDate { get; set; }
public virtual User Owner { get; set; }//It is Forign key with user table
}
[Table("User")]
public class User
{
[Key]
public Int64 UserId { get; set; }
public String UserName { get; set; }
public String LoweredUserName { get; set; }
public String FirstName { get; set; }
public String LastName { get; set; }
public String Email { get; set; }
public String LoweredEmail { get; set; }
public String Password { get; set; }
public String PasswordSalt { get; set; }
public String PasswordQuestion { get; set; }
public String PasswordAnswer { get; set; }
public Boolean IsApproved { get; set; }
public Boolean IsLocked { get; set; }
public DateTime LastActivityDate { get; set; }
public DateTime LastLoginDate { get; set; }
public DateTime CreateDate { get; set; }
public virtual Business Bussines { get; set; }
}
when I want to add information:
user.Business = new Business
{
OwnerId = user.UserId,
LegalTypeId = business.LegalTypeId,
BusinessTypeId = business.BusinessTypeId,
MainIndustryFieldId = business.MainIndustryFieldId,
NameNative = business.NameNative,
NameEnglish = business.NameEnglish,
Logo = business.Logo,
CreateDate = DateTime.Now
};
ctx.SaveChanges();
I get the following error:
Cannot insert explicit value for identity column in table 'Business'
when IDENTITY_INSERT is set to OFF.
In database column identity specification business chose is Identity Yes.
Somebody can tell what to do.

Answer 1

Can you make sure that in your EDMX model, your BusinessId is set to be handled by the database (property StoreGeneratedPattern = Identity)?? Also: why is your primary key nullable (long?) - makes no sense whatsoever. Your primary key must never be null !

Answer 2

BusinessId can not be empty/null since you have not specified that it should be autogenerated by Sql Server (which Identity means).
Since you are using Code First to generate your database, just change to:
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public long? BusinessId { get; set; }

Answer 3

override OnModelCreating in DbContext and add in it following Fluent API:
modelBuilder.Entity<Business>().HasRequired(m => m.Address).WithRequiredPrincipal(m => m.Business).WillCascadeOnDelete(true);