//DataContext
public class BlogContext : DbContext
{
       
       public DbSet<Blog> Blog { get; set; }
       public DbSet<Post> Posts { get; set; }
       protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
       { 
           string connectionString = "...";
           optionsBuilder.UseFirebirdSql(connectionString);   
       }
       protected override void OnModelCreating(ModelBuilder modelo)
       {
           //Fluent Api
           modelo.Entity<Blog>(entity =>
           {
               entity.HasIndex(e => e.BlogId)
                   .HasName("Id")
                   .IsUnique();
           });
       }
   }

   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; }
   }
}     

//Sample Use
 var cx = new BlogContext();  
 
 //one
 cx.Blog.Add(new Blog
 {
     Url = "https://github.com/ralmsdeveloper/EntityFrameworkCore.FirebirdSQL"
 });
 cx.SaveChanges();
 
 //Range
 var RangeBlog = new List<Blog>
 {
      new Blog{ Url="https://github.com/ralmsdeveloper/EntityFrameworkCore.FirebirdSQL"  },
      new Blog{ Url="https://github.com/ralmsdeveloper/"  },
      new Blog{ Url="https://blog.ralms.net"  },
      new Blog{ Url="https://ralms.net"  } 
 };
 cx.Blog.AddRange(RangeBlog);
 cx.SaveChanges();

//Sample Use
 var cx = new BlogContext();  
  
 var blog = cx.Blog.Find(1);
 cx.Attach(registro);
 blog.Url = "www.ralms.net";
 cx.SaveChanges(); 

//Sample Use
 var cx = new BlogContext();  
  
 var blog = cx.Blog.Find(1);
 cx.Delete(blog); 
 cx.SaveChanges(); 

//Sample Use
 var cx = new BlogContext();  
  
 var blog = cx.Blog.Where(p => p.BlogId == 1).ToList();