Entity Framework - Include Multiple Levels of Properties

Question

The Include() method works quite well for Lists on objects. But what if I need to go two levels deep? For example, the method below will return ApplicationServers with the i

Answer 1

I made a little helper for Entity Framework 6 (.Net Core style), to include sub-entities in a nice way.

It is on NuGet now : Install-Package ThenInclude.EF6

using System.Data.Entity;

var thenInclude = context.One.Include(x => x.Twoes)
    .ThenInclude(x=> x.Threes)
    .ThenInclude(x=> x.Fours)
    .ThenInclude(x=> x.Fives)
    .ThenInclude(x => x.Sixes)
    .Include(x=> x.Other)
    .ToList();

The package is available on GitHub.

Answer 2

I'm going to add my solution to my particular problem. I had two collections at the same level I needed to include. The final solution looked like this.

var recipe = _bartendoContext.Recipes
    .Include(r => r.Ingredients)
    .ThenInclude(r => r.Ingredient)
    .Include(r => r.Ingredients)
    .ThenInclude(r => r.MeasurementQuantity)
    .FirstOrDefault(r => r.Id == recipeId);
if (recipe?.Ingredients == null) return 0m;
var abv = recipe.Ingredients.Sum(ingredient => ingredient.Ingredient.AlcoholByVolume * ingredient.MeasurementQuantity.Quantity);
return abv;

This is calculating the percent alcohol by volume of a given drink recipe. As you can see I just included the ingredients collection twice then included the ingredient and quantity onto that.