public void TestCreateBookWithExistingAuthorSavedToDatabase()
{
//SETUP
var options = SqliteInMemory.CreateOptions <EfCoreContext>();
using var context = new EfCoreContext(options);
context.Database.EnsureCreated();
context.Add(new Author {
Name = "Mr. A"
});
context.SaveChanges();
//ATTEMPT
var foundAuthor = context.Authors //#A
.SingleOrDefault(author => author.Name == "Mr. A"); //#A
if (foundAuthor == null) //#A
{
throw new Exception("Author not found"); //#A
}
var book = new Book //#B
{ //#B
Title = "Test Book", //#B
PublishedOn = DateTime.Today //#B
}; //#B
book.AuthorsLink = new List <BookAuthor> //#C
{ //#C
new BookAuthor //#C
{ //#C
Book = book, //#C
Author = foundAuthor //#C
} //#C
}; //#C
context.Add(book); //#D
context.SaveChanges(); //#D
/************************************************************
#A You reads in the author with a check that the author was found
#B This creates a book in the same way as the previous example
#C This adds a AuthorBook linking entry, but it uses the Author that is already in the database
#D This adds the new book to the DbContext Books property and call SaveChanges
* *********************************************************/
//VERIFY
context.Books.Count().ShouldEqual(1); //#E
context.Authors.Count().ShouldEqual(1); //#F
}
public void TestCreateBookWithExistingAuthorSavedToDatabase()
{
//SETUP
var options = SqliteInMemory.CreateOptions <EfCoreContext>();
using var context = new EfCoreContext(options);
context.Database.EnsureCreated();
var author = new Author {
Name = "Existing Author"
}; //#A
context.Add(author); //#A
context.SaveChanges(); //#A
var book = new Book //#B
{ //#B
Title = "Test Book", //#B
PublishedOn = DateTime.Today //#B
}; //#B
book.AuthorsLink = new List <BookAuthor> //#C
{ //#C
new BookAuthor //#C
{ //#C
Book = book, //#C
Author = author //#C
} //#C
}; //#C
//ATTEMPT
context.Add(book); //#D
context.SaveChanges(); //#D
/************************************************************
#A This creates an author and saves it to the database
#B This creates a book in the same way as the previous example
#C This adds a AuthorBook linking entry, but it uses the Author that is already in the database
#D This is the same process: add the new book to the DbContext Books property and call SaveChanges
* *********************************************************/
//VERIFY
context.Books.Count().ShouldEqual(1); //#E
context.Authors.Count().ShouldEqual(1); //#F
}
public void TestCreateBookWithExistingAuthorSavedToDatabase()
{
//SETUP
var inMemDb = new SqliteInMemory();
using (var context = inMemDb.GetContextWithSetup())
{
var oneBook =
EfTestData.CreateDummyBookOneAuthor(); //#A
context.Add(oneBook); //#A
context.SaveChanges(); //#A
var book = new Book //#B
{ //#B
Title = "Test Book", //#B
PublishedOn = DateTime.Today //#B
}; //#B
book.AuthorsLink = new List <BookAuthor> //#C
{ //#C
new BookAuthor //#C
{ //#C
Book = book, //#C
Author = oneBook.AuthorsLink //#C
.First().Author //#C
} //#C
}; //#C
//ATTEMPT
context.Add(book); //#D
context.SaveChanges(); //#D
/************************************************************
#A This method creates dummy books for testing. I create one dummy book with one Author and add it to the empty database
#B This creates a book in the same way as the previous example, but sets up its Author
#C This adds a AuthorBook linking entry, but it reads in an existing the Author from the first book
#D This is the same process: add the new book to the DbContext Books property and call SaveChanges
* *********************************************************/
//VERIFY
context.Books.Count().ShouldEqual(2); //#E
context.Authors.Count().ShouldEqual(1); //#F
}
}
