Using Include in Entity Framework Core - asp.net-mvc

Question

Question: How and where the extension method "Include", used in the Index() action method, in the following PostController used in the Inxex.cshtml view shown below? As I understand _context.Posts.Include(p => p.Blog) means include all posts that relate to blogs table. But I don't see use of blog class or blogId property in the Index.cshtml view below?
Background: In an ASP.NET MVC Core - Code First project I'm following this ASP.NET official site tutorial where they have following Model classes for Blog (parent) and Post (child). I then created a controller (shown below) using MVC Controller with Views, using Entity Framework wizard where I selected Post model in the Model dialogbox.:
Model:
using Microsoft.EntityFrameworkCore;
using System.Collections.Generic;
namespace EFGetStarted.AspNetCore.NewDb.Models
{
public class BloggingContext : DbContext
{
public BloggingContext(DbContextOptions<BloggingContext> options)
: base(options)
{ }
public DbSet<Blog> Blogs { get; set; }
public DbSet<Post> Posts { get; set; }
}
public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
public List<Post> Posts { get; set; }
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public int BlogId { get; set; }
public Blog Blog { get; set; }
}
}
PostController:
public class PostsController : Controller
{
private readonly BloggingContext _context;
public PostsController(BloggingContext context)
{
_context = context;
}
// GET: Posts
public async Task<IActionResult> Index()
{
var bloggingContext = _context.Posts.Include(p => p.Blog);
return View(await bloggingContext.ToListAsync());
}
}
Index.cshtml view for Index() action in PostController:
#model IEnumerable<ASP_Core_Blogs.Models.Post>
#{
ViewData["Title"] = "Index";
}
<h2>Index</h2>
<p>
<a asp-action="Create">Create New</a>
</p>
<table class="table">
<thead>
<tr>
<th>
#Html.DisplayNameFor(model => model.Content)
</th>
<th>
#Html.DisplayNameFor(model => model.Title)
</th>
<th></th>
</tr>
</thead>
<tbody>
#foreach (var item in Model) {
<tr>
<td>
#Html.DisplayFor(modelItem => item.Content)
</td>
<td>
#Html.DisplayFor(modelItem => item.Title)
</td>
<td>
<a asp-action="Edit" asp-route-id="#item.PostId">Edit</a> |
<a asp-action="Details" asp-route-id="#item.PostId">Details</a> |
<a asp-action="Delete" asp-route-id="#item.PostId">Delete</a>
</td>
</tr>
}
</tbody>
</table>

Answer 1

Since you're not accessing the Blog property, it's better not to use Include(p => p.Blog). This will add an extra join that isn't required.
However, if you'll reference it in each table row, then it's preferred to include it to avoid lazy loading issues.