Entity Framework include collection/reference where - entity-framework

Question

I'm trying to select the latest version of all my clients and load each object with the latest version of their respective payments and the payments respective segment name.
It's a .net Core 2.0 project.
The controller is using:
using System;
using System.Linq;
using Microsoft.AspNetCore.Mvc;
using CBFU.Data;
using CBFU.Models;
using Microsoft.EntityFrameworkCore;
A client is created with no foreign keys.
A payment is created with af the foreign keys: ClientId and SegmentId.
A segment is created with no foreign keys.
I'm thinking something like:
var clients = _context.Clients
.Where(client => client.IsLatest == 1)
.Include(client => client.Payments
.Select(payment => payment.IsLatest == 1)
.Select(payment => payment.Segment))
.ToList();
But that does not work. Below I've listed af few of the things I tried and if it worked. I've no examples with .ThenInclude as my intelliSense does not respond to it.
// 1 This works: Loading payments into clients
var clients = _context.Clients
.Where(client => client.IsLatest == 1)
.Include(client => client.Payments)
.ToList();
// 2 This does NOT work: Loading payment with IsLatest == 0 into clients
var clients = _context.Clients
.Where(client => client.IsLatest == 1)
.Include(client => client.Payments
.Select(p => p.IsLatest == 1))
.ToList();
// 3 This does NOT work: Loading segment into payments into clients
var clients = _context.Clients
.Where(client => client.IsLatest == 1)
.Include(client => client.Payments
.Select(p => p.Segment == 1))
.ToList();
Both 2 and 3 gives the same error:
The property expression 'client => {from Payment payment in client.Payments select ([payment].IsLatest == 1)}' is not valid. The expression should represent a property access: 't => t.MyProperty'.For more information on including related data, see http://go.microsoft.com/fwlink/?LinkID=746393.
Source =< Cannot evaluate the exception source>
My classes looks as follows:
public class Client
{
public int Id { get; set; }
public int IsLatest { get; set; }
public ICollection<Payment> Payments { get; set; }
}
public class Payment
{
public int Id { get; set; }
public Client Client { get; set; }
[Required]
[Display(Name = "Client")]
public int ClientId { get; set; }
public Segment Segment { get; set; }
[Required]
[Display(Name = "Segment")]
public int SegmentId { get; set; }
public int IsLatest { get; set; }
}
public class Segment
{
public int Id { get; set; }
public string Name { get; set; }
}

Answer 1

Filtered Includes were never supported in pre EF Core, and (as of current v2.0) are still not supported by EF Core. EF Core 2.0 introduced Model-level query filters, but they apply for all queries and have to be specifically turned off when not needed. Also are not flexible enough to handle dynamic query level filtering.
What you can do though is to utilize a combination of the so called navigation property fixup, eager loading and filtering loaded entities techniques described in the Loading Related Data section of the documentation:
var clientQuery = _context.Clients
.Where(client => client.IsLatest == 1);
var clients = clientQuery.ToList();
clientQuery
.SelectMany(c => c.Payments)
.Include(p => p.Segment)
.Where(p => p.IsLatest == 1)
.Load();