Entity Framework 4.0 CTP5 Many to Many relation ship with a help table?

Question

i have a question about EF4 again :) sorry i can't find any thing on the net.

The question is i am using CTP5 Code Only to map (many to many), how do i do it???

But i am doing the old fashion way, i mean i have three tables:

1. Users
2. Companies.
3. UsersToCompanies -> (UserId, CompanyId)

How do i map this, it will be really appreciated if you would show me the code example to it, from POCO's to Mapping.

---

This is the error i receive...

This is my entities
public class User 
{
   public int UserId { get; set; }
   public int? UserRoleId { get; set; }
   public string UserName { get; set; }
   public string UserPassword { get; set; }
   public DateTime InsertDate { get; set; }
   public virtual UserRole UserRole { get; set; }

   //this is my many to many prop
   public virtual ICollection<Company> Companies { get; set; }
}

public class Company
{
   public int CompanyId { get; set; }
   public string CompanyNameHe { get; set; }
   public string CompanyNameEn { get; set; }
   public string CompanyParent { get; set; }
   public DateTime InsertDate { get; set; }

   //this is my many to many prop
   public virtual ICollection<User> Users { get; set; }
}

/*relationship map*/
public class UsersCompanies
{
   public int Id { get; set; } 
   public int UserId { get; set; } 
   public int CompanyId { get; set; } 
}
    //mapping
 public class CompanyMap :  BaseConfig<Company>
 {
    public CompanyMap()
    {
        /*Identity*/
        HasKey(c => c.CompanyId);
        Property(c => c.CompanyId).HasDatabaseGenerationOption(DatabaseGenerationOption.Identity).HasColumnName("COMPANY_ID");

        /*Have default values*/
        Property(c => c.InsertDate).HasDatabaseGenerationOption(DatabaseGenerationOption.Computed).HasColumnName("INSERT_DATE");

        /*simple scalars*/
        Property(c => c.CompanyNameHe).HasMaxLength(32).IsRequired().HasColumnName("COMPANY_NAME_HE");
        Property(c => c.CompanyNameEn).HasMaxLength(32).IsRequired().HasColumnName("COMPANY_NAME_EN");
        Property(c => c.CompanyParent).HasMaxLength(32).IsRequired().HasColumnName("COMPANY_PARENT");
        ToTable("CMS_COMPANY", "GMATEST");
    }
 }


public class UserMap : BaseConfig<User>
{
   public UserMap()
   {
       /*Identity*/
       HasKey(c => c.UserId);
       Property(c => c.UserId).HasDatabaseGenerationOption(DatabaseGenerationOption.Identity).HasColumnName("USER_ID");

       /*Have default values*/
       Property(c => c.InsertDate).HasDatabaseGenerationOption(DatabaseGenerationOption.Computed).HasColumnName("INSERT_DATE");

       /*simple scalars*/
       Property(c => c.UserName).HasMaxLength(25).IsRequired().HasColumnName("USER_NAME");
       Property(c => c.UserPassword).HasMaxLength(25).IsRequired().HasColumnName("USER_PASSWORD");
       Property(c => c.UserRoleId).IsRequired().HasColumnName("USER_ROLE_ID");

       /*relationship*/
       HasRequired(u => u.UserRole).WithMany().HasForeignKey(t => t.UserRoleId);


       HasMany(p => p.Companies).WithMany(c => c.Users).Map(mc =>
       {
           mc.ToTable("UsersCompanies");
           mc.MapLeftKey(p => p.UserId, "CompanyId");
           mc.MapRightKey(c => c.CompanyId, "UserId");
       });
       ToTable("CMS_USERS", "GMATEST");
   }
}

public class UsersCompaniesMap : BaseConfig<UsersCompanies>
{
   public UsersCompaniesMap()
   {
       /*Identity*/
       HasKey(k => k.Id);
       Property(c => c.Id).HasDatabaseGenerationOption(DatabaseGenerationOption.Identity).HasColumnName("ID");

       Property(c => c.UserId).IsRequired().HasColumnName("USER_ID");
       Property(c => c.CompanyId).IsRequired().HasColumnName("COMPANY_ID");

       ToTable("CMS_USERS_TO_COMPANIES", "GMATEST");
   }
}

---

Here's the error I get:

'((new System.Linq.SystemCore_EnumerableDebugView(ctx.FindAll())).Items[0]).Companies' threw an exception of type 'System.Data.EntityCommandExecutionException'

Inner exception: ORA-00942: table or view does not exist

Answer 1

The answer for my problem, i have to say many thanks to you all, but Andrey from Devart, have given me the solution, it's simple.

First off all i have to have, three tables Companies, Users, UsersCompanies/

Second off all i have to map the tables to original names of tables example: my users table called in Db like that: CMS_USERS i have to map it with original name. this is the example that i use and it's really works.

HasMany(c => c.Companies)
          .WithMany(u => u.Users)
          .Map(mc =>
          {
              mc.ToTable("CMS_USERS_TO_COMPANIES", "GMATEST");
              mc.MapLeftKey(c => c.UserId, "USER_ID");
              mc.MapRightKey(u => u.CompanyId, "COMPANY_ID");
          });

Thank you all.