Query linq, matching properties

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Query linq, matching properties

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#1 by (1 votes)
#2 by (0 votes)

1

I'm working with Entity Framework code first, I'm putting together a query but from my entity I only need the first two attributes for which I had to create another class with the attributes I need to not bring me the whole entity.

public class Proveedor
{
    public int ProveedorId { get; set; }
    public string RazonSocial { get; set; }
    public string DocumentoIdentidad { get; set; }
    public string Direccion { get; set; }
    public string Fijo { get; set; }
    public string Celular { get; set; }
    public string Representante { get; set; }
    public string Email { get; set; }

    public virtual ICollection<Producto> Productos { get; set; }
    public virtual ICollection<Marca> Marcas { get; set; }
}

Extended class

public class ProveedorExtend 
{
    public int Id { get; set; }
    public string Descripcion { get; set; }
}

I need to match the properties

public IEnumerable<ProveedorExtend> SelectList(int? codigo, string nombre)
    {
        var result = (from p in Context.Proveedores
                      select new ProveedorExtend()
                      {
                          Id = p.ProveedorId,
                          Descripcion = p.RazonSocial
                      })

So that you can apply a Where

where ((!codigo.HasValue) || (p.Codigo.Contains(codigo.Value)))
                        && ((nombre == null) || (p.Nombre.Contains(nombre)))
                 select p).ToList();

How can I do this query?

public List<ProveedorExtend> SelectList(int? codigo, string nombre)
{
    using(DbContext context = new DbContext())
    {
        var result = (from p in context.Proveedores
                     where ((!Id.HasValue) || (p.Id.Contains(Id.Value)))
                            && ((Descripcion == null) || (p.Descripcion.Contains(nombre)))
                     select p).ToList();;

        return result;
    }
}

But I need to match the entities before making that query. I hope to have explained. The description would be: I try to make a query that serves me for two conditions through that query I can ask for the id, how can I ask for the description, like for example if I have a table that has, 1- Juan 2-Miguel 3-Marcos 4 José What I want is to do a like, researching constains is the one that makes a like, but the problem is that I can not apply to the whole entity, if it were SQL I would do a query SELECT Id, description FROM Suppliers, .... but in EF I can not do that would bring me the whole entity that is why I have to separate it in my SupplierExtend class where I put the attributes I need but for it to work I have to match it to the Suppliers, in my Context I do not see VendorExtends I can not apply directly.

I am left with the query thanks to Leandro and Carlos Muñoz.

public IEnumerable<ProveedorExtend> SelectList(int? codigo, string nombre)
    {
        var result = (from p in Context.Proveedores
                      where ((!codigo.HasValue) || (p.ProveedorId == codigo.Value)) &&
                      ((nombre == null) || (p.RazonSocial.Contains(nombre)))
                      select new ProveedorExtend()
                      {
                          Id = p.ProveedorId,
                          Descripcion = p.RazonSocial
                      }).ToList();
        return result;          
    }

c# entity-framework-6 visual-studio-2015

asked by Pedro Ávila 24.05.2016 в 23:24

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2 answers

1

Note: I think you have syntax errors in your code. I will place the code according to how it seems it should be.

If you need to convert Proveedor in ProveedorExtend before to apply the where I recommend the syntax using lambdas:

public List<ProveedorExtend> SelectList(int? codigo, string nombre)
{
    using(DbContext context = new DbContext())
    {
        return context.Proveedores
            .Select(p => new ProveedorExtend
            {
                Id = p.ProveedorId,
                Descripcion = p.RazonSocial
            })
            .Where(p =>
                (!codigo.HasValue || p.Id == codigo.Value) &&
                (nombre == null || p.Descripcion.Contains(nombre)
            )
            .ToList();
    }
}

On the other hand this is not necessary you can apply the .Where() to the original collection and then project its properties in the new class.

public List<ProveedorExtend> SelectList(int? codigo, string nombre)
{
    using(DbContext context = new DbContext())
    {
        return context.Proveedores
            .Where(p =>
                (!codigo.HasValue || p.ProveedorId == codigo.Value) &&
                (nombre == null || p.RazonSocial.Contains(nombre)
            )
            .Select(p => new ProveedorExtend
            {
                Id = p.ProveedorId,
                Descripcion = p.RazonSocial
            })
            .ToList();
    }
}

answered by 24.05.2016 в 23:51

Call JavaScript in a bean NULL data in Delphi 7 [closed]

score 0 · Accepted Answer

Seria

public List<ProveedorExtend> SelectList(int? codigo, string nombre)
{
    using(DbContext context = new DbContext())
    {
        var result = (from p in context.Proveedores
                     where ((!Id.HasValue) || (p.Id.Contains(Id.Value)))
                            && ((Descripcion == null) || (p.Descripcion.Contains(nombre)))
                     select new ProveedorExtend()
                      {
                          Id = p.ProveedorId,
                          Descripcion = p.RazonSocial
                      }).ToList();;

        return result;
    }
}

As you will see in the select you define the new of the class ProveedorExtend