Modify generic method to merge information into classes

Question

I’m a first-time sailor with the Entityframework and I’m working with a class USUARIO who inherits from PESSOA.

There are other classes like PESSOATIPO, PESSOAFISICA, PESSOAJURIDICA, etc., the problem is that when I carry my DataGridView, Entityframework cannot separate the data from each table and position the fields correctly within the lines. See how PESSOAFISICA was should be presented the fields NOMECOMPLETO, APELIDO And DATANASCIMENTO.

This is because I have a generic function that returns me all this. I wonder if it gives to implement/amend the function below to pass some kind of select (Lambda) to return me columns in the order I want, and so the DataGridview be loaded correctly and the charging has a good performance?

Example:

Usuario.Select(x=> x.USuarioId, 
               x.PessoaFisica.NomeCompleto, 
               x.PessoaFisica.Apelido, 
               x.PessoaFisica.DataNascimento).

I mean, something like.

public List<TEntity> GetAll(Expression<Func<TEntity, bool>> Predicate)
{
    var query = Context.Set<TEntity>().Where(Predicate).ToList();
    return query;
}

Answer 1

Yes, there is a way to bring you a list with type created at runtime (can also be created a class representing this new data model), create a method with the code below, where TResult is a new data type that will be created on output and can assign the new list in the DataGridView

public List<TResult> GetAll<TResult>(Expression<Func<TEntity, bool>> predicate, 
                                     Expression<Func<TEntity, TResult>> select)
{
    var query = Context.Set<TEntity>()
                       .Where(predicate)
                       .Select(select) 
                       .ToList();
    return query;
}

---

In the method call would be:

.GetAll(x => x.UsuarioId == 1, s = new {
        s.UsuarioId, ... //e continua colocando os dados da relação e precisa
});

_{Observing: I believe I should implement the interface to propagate in the implementing classes.}

References:

• Expression Class
• What are lambda expressions?
• Pass in an Expression to Linq’s Select
• Introduction to LINQ queries (C#)
• Basic LINQ query operations (C#)