Cannot create the right table using code first

Question

I'm having some serious issues trying to create a table using code first. So this is what I have:

public class Pessoa
{
    [Key]
    public int PessoaId { get; set; }
    public virtual Empresa Empresa { get; set; }
    ...
}


public class Empresa
{
    [DatabaseGenerated(DatabaseGeneratedOption.Computed)]
    public int EmpresaId { get; set; }
    public virtual List<FuncionarioFree> FuncionarioFree { get; set; }
    public virtual List<FuncionarioPagante> FuncionarioPagante { get; set; }
    [Key,ForeignKey("Pessoa")]
    public int PessoaId { get; set; }
    [Required]
    public virtual Pessoa Pessoa { get; set; }
    ...
}

public class FuncionarioPagante
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int FuncionarioPaganteId { get; set; }
    public int PessoaId { get; set; }
    [ForeignKey("PessoaId")]
    public virtual Pessoa Pessoa { get; set; }
    public int EmpresaId { get; set; }
    [ForeignKey("EmpresaId")]
    public virtual Empresa Empresa { get; set; }
}

Now for what I need:

Pessoa may or may not have a Empresa(company). And Empresa has a list of FuncionarioPagante(employees).

Now when i try to insert a new FuncionarioPagante:

 var novoFuncionario = new FuncionarioPagante()
 {
        EmpresaId = empresaId,
        Pessoa = pessoaUnidade.Pessoa,
        PessoaId = pessoaUnidade.PessoaId
 };

 _contexto.FuncionarioPagante.Add(novoFuncionario);
 _contexto.SaveChanges();

It is trowing this error: (Note: in this case, both Pessoa and Empresa already exists in the db)

"The INSERT statement conflicted with the FOREIGN KEY constraint \"FK_dbo.FuncionarioFree_dbo.Empresa_EmpresaId\". The conflict occurred in database \"...", table \"dbo.Empresa\", column 'PessoaId'.\r\nThe statement has been terminated."

EDIT: I did some more tests and it works when i try to insert a new FuncionarioPagante with a Pessoa that has a Empresa. But that doesn't make sense to me. The Pessoa that i am inserting shouldn't had to have a Empresa in order to be inserted into a list of FuncionarioPagante in an Empresa of someone else.

EDIT 2: When i insert it with Empresa it works as well, like this:

var empresa = _contexto.Empresa.Where(x => x.EmpresaId == empresaId).FirstOrDefault();

var novoFuncionario = new FuncionarioPagante()
{
    EmpresaId = empresaId,
    Pessoa = pessoaUnidade.Pessoa,
    Empresa = empresa,
    PessoaId = pessoaUnidade.PessoaId
};

But the value inserted in EmpresaId changes to the value of PessoaId of the owner of the Empresa after SaveChanges()

Answer 1

Its likely because the state of the Pessoa is also changing to "added". Remove the line

Pessoa = pessoaUnidade.Pessoa,

and only set the ID. That should let it save correctly.

Your object graph is making it look like all entities are new. As an alternative you could explicitly set the Pessoa entity to an object state of "unmodified".

To verify this, before save chagnes you'd do something like (did not compile, but this is close) this...

var tmpState = _contexto.Entity<Pessoa>(pessoaUnidade.Pessoa).ObjectState;
//look at value of tmpState. it likely says "added" and you want it to be "unmodified"

Answer 2

Can you modify the FuncionarioPagante to have a nullable value for EmpresaId

public class FuncionarioPagante
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int FuncionarioPaganteId { get; set; }
    public int PessoaId { get; set; }
    [ForeignKey("PessoaId")]
    public virtual Pessoa Pessoa { get; set; }
    public int? EmpresaId { get; set; }
    [ForeignKey("EmpresaId")]
    public virtual Empresa Empresa { get; set; }
}