static void Main(string[] args)
{
Author existingAuthor;
using (var ctx = new EfTestDbContext())
{
existingAuthor = new Author()
{
Name = "First author"
};
ctx.Add(existingAuthor);
ctx.SaveChanges();
Console.WriteLine($"Saved author ({existingAuthor.Name})");
}
using (var ctx = new EfTestDbContext())
{
var book1 = new Book()
{
Name = "First book",
Author = existingAuthor
};
Console.WriteLine($"Added author ({existingAuthor.Name}) to first book. Author is existing: {ctx.Entry(existingAuthor).IsKeySet}");
ctx.Add(book1);
ctx.SaveChanges();
}
Console.WriteLine("ALL DONE");
}
static void Main(string[] args)
{
using (var ctx = new EfTestDbContext())
{
ctx.Database.EnsureCreated();
}
Author existingAuthor;
using (var ctx = new EfTestDbContext())
{
Console.WriteLine($"Setup:");
var author = new Author {
Name = "An author"
};
Console.WriteLine($" Adding author ({author.Name}) to DB. Author's `IsKeySet`: {ctx.Entry(author).IsKeySet}");
ctx.Add(author);
ctx.SaveChanges();
Console.WriteLine($" Saved author ({author.Name})");
Console.WriteLine($" Retrieving author from DB");
existingAuthor = ctx.Authors.First();
}
using (var ctx = new EfTestDbContext())
{
Console.WriteLine($"Adding new book and new author:");
var book = new Book()
{
Name = "First book",
Author = new Author {
Name = "Another author"
}
};
Console.WriteLine($" Adding a new book with a new author to DB. Book's `IsKeySet`: {ctx.Entry(book).IsKeySet}");
ctx.Add(book);
ctx.SaveChanges();
Console.WriteLine($" Saved");
}
Console.WriteLine($"Database contents:");
using (var ctx = new EfTestDbContext())
{
Console.WriteLine($"Authors:");
foreach (var a in ctx.Authors)
{
Console.WriteLine($" {a.ID} - {a.Name}");
}
Console.WriteLine($"Books & authors:");
foreach (var b in ctx.Books.Include(x => x.Author))
{
Console.WriteLine($" {b.ID} - {b.Name} written by {b.Author.Name}");
}
Console.WriteLine($"");
}
using (var ctx = new EfTestDbContext())
{
Console.WriteLine($"Changing author of the book");
var bookToChange = ctx.Books.First();
bookToChange.Author = existingAuthor;
Console.WriteLine($" Changed book: {bookToChange.ID} - {bookToChange.Name} written by {bookToChange.Author.Name}");
Console.WriteLine($" Existing author's `IsKeySet`: {ctx.Entry(existingAuthor).IsKeySet}");
ctx.SaveChanges();
Console.WriteLine($" Saved changes");
}
using (var ctx = new EfTestDbContext())
{
Console.WriteLine($"Adding a new book with an existing author");
var book = new Book()
{
Name = "First book",
Author = existingAuthor
};
Console.WriteLine($" Added author ({existingAuthor.Name}) to a new book. Author's `IsKeySet`: {ctx.Entry(existingAuthor).IsKeySet}");
ctx.Add(book);
ctx.SaveChanges();
}
Console.WriteLine("ALL DONE");
}