How to get childs of child of a parent Entity Framework

Question

I have 3 tables

Inventarios -> Localizacoes -> Etiquetas

all have one to many relation from left to right

Problem is that i cannot seem to reach Etiquetas

// GET: api/Inventarios public IQueryable<Inventario> GetInventarios() { var inventarios = db.Inventarios.Include(i => i.Localizacoes.Select(l => l.Etiquetas.SelectMany(e => e.Numero))); return inventarios; }

and here are the models

public class Inventario { public int InventarioID { get; set; } public string Colaborador { get; set; } public string Armazem { get; set; } public decimal Total { get; set; } public DateTime Data { get; set; } public ICollection<Localizacao> Localizacoes { get; set; } } public class Localizacao { public int LocalizacaoID { get; set; } public string Referencia { get; set; } public int EtiquetasPorInventariar { get; set; } public int EtiquetasInventariadas { get; set; } public bool IsValid { get; set; } public decimal Precisao { get; set; } public int InventarioID { get; set; } public Inventario Inventario { get; set; } public ICollection<Etiqueta> Etiquetas{ get; set; } } public class Etiqueta { public int EtiquetaID { get; set; } public string Numero { get; set; } public int LocalizacaoID { get; set; } public Localizacao Localizacao { get; set; } }

this is the exception i get on browser console from api request

"The Include path expression must refer to a navigation property defined on the type. Use dotted paths for reference navigation properties and the Select operator for collection navigation properties."

The SelectMany doesn't look right, also that fact you are returning an IQueryable is suspicious — TheGeneral
– TheGeneral, Commented Mar 16, 2019 at 23:57
Why so? I think it was generated from Controller class, i can't recall though — Jackal
– Jackal, Commented Mar 16, 2019 at 23:59
it is not clear from your question what exactly you want to get? All rows from Etiqueta? You don't have any where clause. — Felix
– Felix, Commented Mar 17, 2019 at 0:12

TheGeneral · Accepted Answer · 2019-03-17 00:12:23Z

My assumption is you are using IQueryable for OData support

That aside, there are 2 things i am seeing here that are not looking quite right

The first, is the SelectManyit should probably be Select

var inventarios = db.Inventarios.Include(i => i.Localizacoes.Select(l => l.Etiquetas.Select(e => e.Numero)));

The second, is you are returning IQueryable, i am not really sure this will traverse the object graph.

As a test you could do something like this

return inventarios.ToList().AsQuerable();

yes it worked with select, i'm still a beginner using linq though. But either way, it's return json data in correct format and displaing in a table with 2 nested tables

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