Doubt about Entity Modeling

Question

I have an entity called Requests that satisfies the following business:

1. A request is made by an Employee(Entity), then it is changed by another Employee and then confirmed by a third Employee.

2. In a request I am sending a Client(Entity) from one Bed(Entity) to another Bed(Entity). Below is the current mapping:

   using System;
   using SG.ProjetoTCC.Domain.Entities.Local;
   
   namespace SG.ProjetoTCC.Domain.Entities
   {
       public class Solicitacao
       {
           public Solicitacao()
           {
               SolicitacaoId = Guid.NewGuid();            
   
           }
           public Guid SolicitacaoId { get; set; }
           public DateTime DataSolicitacao { get; set; }
   
           public Guid FuncionarioSolicitanteId { get; set; }
           public virtual Funcionario FuncionarioSolicitante { get; set; }
   
           public TipoSolicitacao TipoSolicitacao { get; set; }
           public Guid ClienteId { get; set; }
           public virtual Cliente Cliente { get; set; }
   
           public Guid LeitoLocalId { get; set; }
           public virtual Leito LeitoLocal { get; set; }
   
           public Guid LeitoDestinoId { get; set; }
           public virtual Leito LeitoDestino { get; set; }
           public DateTime DataReserva { get; set; }
   
           public Guid FuncionarioReservaId { get; set; }
           public virtual Funcionario FuncionarioReserva { get; set; }
           public DateTime DataConclusao { get; set; }
   
           public Guid FuncionarioConclusaoId { get; set; }
           public virtual Funcionario FuncionarioConclusao { get; set; }
           public DateTime Tempo { get; set; }
   
       }
   }
   

   A Solicitation does not have many (Ienumerable) Employees, it has 3 employees, which are: Functionary (who requested a bed), Functionary(who reserved the bed) and Functionconclusion(who placed the client in the destination Bed), and also 2 Beds; Lectern, and Leitodestino.

3. Is my design correct? I should use a Collection(Bed) and a Collection(Employee)?

I’m sorry if you got too confused, but I think you can understand the way I explained it.

Thank you,

Hugs.

Answer 1

@Samuelgomes, is correct yes.

These properties are what we call Propriedades de Navegação, they allow us to quickly access another Entity that is connected to it.

For example, In the Entity Solicitacao we have a call navigation property FuncionarioSolicitante, this property allows us to quickly access the Employee who requested this Request. Like each Solicitacao may have only 1 Official Solicitante then it doesn’t need to be a list.

As all navigation should allow the flow of both sides, the Entity Funcionariomust have a property called SolicitacoesSolicitante, that allows you to quickly access all Solicitacao that he held. As an employee can perform N requests, this property must be a collection (DbSet).

This at no time prevents the Funcionario cannot be the Requester and the Deliverer of the same Solicitacao, but we will have distinct navigation properties, as they are distinct navigation flows.

Usually each FK in the Database will give rise to a Navigation property in the entities involved, as in the example below:

Foreign Keys

1:N FK_Funcionario_Solicitacao_Solicitante (1 Staff -> N Request) 1:N FK_Funcionario_Solicitacao_Reserva (1 Staff -> N Request) 1:N FK_Funcionario_Solicitacao_Conclusao (1 Staff -> N Request)

Entity - Employee

public virtual DbSet<Solicitacao> SolicitacoesSolicitante { get; set; }
public virtual DbSet<Solicitacao> SolicitacoesReserva { get; set; }
public virtual DbSet<Solicitacao> SolicitacoesConclusao { get; set; }

Entity - Request

public virtual Funcionario FuncionarioSolicitante { get; set; }
public virtual Funcionario FuncionarioReserva { get; set; }
public virtual Funcionario FuncionarioConclusao { get; set; }