Problem saving

Question

Only a form that is returning me this mistake, the question that I do not know what can be or how to fix, some ask to cascade the relationship that is already.

Nhibernate.Transientobjectexception: Object References an Unsaved Transient instance - save the Transient instance before Flushing or set Cascade action for the Property to Something that would make it autosave. Type: Blogweb.Models.Vehicle, Entity: Blogweb.Models.Vehicle

Error return line:

public void Adiciona(Abastecimento abastecimento)
    {
        ITransaction tx = session.BeginTransaction();
        session.Save(abastecimento);
        tx.Commit();
    }

Vehicle Mapping:

public class VeiculoMapping : ClassMap<Veiculo>
{
    public VeiculoMapping()
    {
    Id(p => p.Id).GeneratedBy.Identity();
    Map(p => p.NCarro);
    Map(p => p.Modelo);
    Map(p => p.Ano);

    }
}

Veiculo Model:

public class Veiculo
{
    public virtual int Id { get; set; }
    [Required]
    public virtual int NCarro { get; set; }
    [Required]
    public virtual string Modelo { get; set; }
    public virtual int Ano { get; set; }
}

Supply Mapping:

public class AbastecimentoMapping : ClassMap <Abastecimento>
    {
        public AbastecimentoMapping()
        {
            Id(a => a.Id).GeneratedBy.Identity();
            Map(a => a.DtAbastecido);
            Map(a => a.Litro);
            Map(a => a.VlrUnit);
            Map(a => a.Km);
            Map(a => a.TotalGasto);
            Map(a => a.Km_Andado);
            References(a => a.NomeProduto, "NomeProdutoId");
            References(a => a.Autor, "AutorId");
            References(a => a.NumCarro, "NumCarroId");
        }
    }

Abastecimento Model:

public class Abastecimento
{
    public virtual int Id { get; set;}
    [Required]
    public virtual int Litro { get; set; }
    public virtual DateTime? DtAbastecido { get; set; }
    public virtual decimal VlrUnit { get; set; }
    public virtual int Km { get; set; }
    public virtual decimal TotalGasto { get; set; }
    public virtual int Km_Andado { get; set; }
    public virtual Usuario Autor { get; set; }
    public virtual Compra NomeProduto { get; set; }
    public virtual Veiculo NumCarro { get; set; }
}

Answer 1

You are saving an entity, which has a relationship with an entity that has changed but has not been saved before.

If this is the case, you have two options:

• Save the other entity before saving this one;

• Map the relationship as cascade, so that in such a situation the other related entity is also saved.

Speaking of Easter

For every basic operation of the Nhibernate session - including Persist (), Merge (), SaveOrUpdate (), Delete (), Lock (), Refresh (), Evict (), Replicate () - there is a corresponding cascade style. Respectively, cascading styles are called persist, merge, save-update, delete, block, update, expel, replicate. The cascading style for Save () and Update () is save-update; to SaveAndUpdateCopy () is merged; and PersistOnFlush () is persistent. And removing is an alias to delete.

If you want an operation to be cascaded over an association, you should indicate this in the mapping document. For example:

<one-to-one name="person" cascade="persist"/>

Cascading styles of mine combined:

<one-to-one name="person" cascade="persist,delete,lock"/>

You can use cascade = "all" to specify that all operations must be cascaded over the association. The cascade padrão = "none" specifies that no operation should be cascaded.

I recommend reading more in this post in English HERE