Model.cs

using System.Collections.Generic;
using System.ComponentModel;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;

namespace EFGetStarted
{
    public class BloggingContext : DbContext
    {
        public DbSet<Blog> Blogs { get; set; }
        public DbSet<Post> Posts { get; set;  }

        protected override void OnConfiguring(DbContextOptionsBuilder options)
            => options.UseSqlite("Data Source=blogging.db");

        public class Blog
        {
            public int BlogId { get; set; }
            public string Url { get; set; }
            public List<Post> Posts { get; } = new List<Post>();
        }

        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; }
        }
    }
}