Entity Framework Error Updating Master Details Items

Question

Hi everybody im trying to add new items to master detail records and i get the error:

The INSERT statement conflicted with the FOREIGN KEY constraint "invOrden_InvOrdenDet_FK1". The conflict occurred in database "InventarioSIAIplus", table "dbo.InvOrden", column 'IDorden'. The statement has been terminated.

This error Happens when i add a new item to the detail.

Thanks for any help. CODE I'M USING FOR ADDING AND UPDATING THE THE DATA: InventarioSIAIplusEntities SIAplusContext = (InventarioSIAIplusEntities)(Session["context"]); InvOrden orden;

        if (txtIDorden.Text.Trim() == "")
        {
             orden = new InvOrden();
             orden.IDcentro = Convert.ToInt32(ddlCentros.SelectedValue);
             orden.estado = ddlEstadoOrden.SelectedValue;
             orden.fecha = DateTime.Now;
             orden.comentario = txtComentarioOrden.Text;
             orden.usuarioCrea = "Jeanc";                
             SIAplusContext.AttachTo("InvOrden",orden);              
        }
        else
        {
             int idorden = Convert.ToInt32(txtIDorden.Text.Trim());
             orden = SIAplusContext.InvOrdenes.Where(c => c.IDorden == idorden).First();
                //orden.lo.getOrden());                
             orden.estado = ddlEstadoOrden.SelectedValue;
             orden.fecha = DateTime.Now;
             orden.comentario = txtComentarioOrden.Text;
             orden.usuarioCrea = "Jeanc";

        }

        foreach (var item in DetalleMedicamentosOrden)
        {
            if (item.InvOrdenReference.Value == null)
            {
                item.InvOrden = orden;

            }
        }

        SIAplusContext.SaveChanges();

CODE FOR ADDING ITEMS TEMPORARY TO THE DETAIL

InventarioSIAIplusEntities SIAplusContext = (InventarioSIAIplusEntities)(Session["context"]); List meds = DetalleMedicamentosOrden;

         //Datos Detalle
        InvOrdenDet ordenDetalle = new InvOrdenDet();            
        ordenDetalle.cantidadSol = uscAgregarMedicamentos1.Cantidad;
        ordenDetalle.cantidadApr = uscAgregarMedicamentos1.CantidadAprobada;

        ordenDetalle.comentario=uscAgregarMedicamentos1.Comentario;
        ordenDetalle.comentario = uscAgregarMedicamentos1.Comentario;
        ordenDetalle.IDmedicamento=uscAgregarMedicamentos1.IDmedicamento;

        //Agrego el detalle a la lista de detalles que se va guardando en la memoria.
        meds.Add(ordenDetalle);

        //Paso la lista con el nuevo objecto actualizada.
        DetalleMedicamentosOrden = meds;

        //Consulto la lista con para hacer una proyeccion del query y trae el nombre del medicamento
        var medInfo = from a in DetalleMedicamentosOrden                          
                     select new { a,  a.cantidadSol, a.cantidadApr };

        //Cargo la data en el gridview.
        gvMedicamentosOrden.DataSource = medInfo;
        gvMedicamentosOrden.DataBind();

        //Mando a mostrar 
        mpePnMedicamentos.Show();

Answer 1

The error basically means that you are trying to add a row to the detail table without providing a legit FK from the master table.
I am guessing this happens when your if code block (txtIDorden.Text.Trim() == "") is executing which means you are dealing with a brand new orden object that does not have any EntityKey before saving. I can see that you are trying to explicitly set the detail object to the master through InvOrdenReference which does not make sense in your scenario. What I suggest is that set it through navigation property and let EF fix it up for you at runtime. So your foreach should be something like this:

foreach (var item in DetalleMedicamentosOrden) {
    if (item.InvOrdenReference.Value == null) {
        item.InvOrden = orden;                  
     }
}