public void TestRightWayToSetupRelationshipsOk()
{
//SETUP
var showlog = false;
var options = this.CreateUniqueClassOptionsWithLogging <EfCoreContext>(log =>
{
if (showlog)
{
_output.WriteLine(log.Message);
}
});
using (var context = new EfCoreContext(options))
{
context.Database.EnsureClean();
showlog = true;
//ATTEMPT
var book = new Book //#A
{ //#A
Title = "Test", //#A
Reviews = new List <Review>() //#A
}; //#A
book.Reviews.Add( //#B
new Review {
NumStars = 1
}); //#B
context.Add(book); //#C
context.SaveChanges(); //#D
/*********************************************************
#A This creates a new Book
#B This adds a new Review to the Book's Reviews navigational property
#C The Add method says that the entity instance should be Added to the appropriate row, with any relationships either added or updated
#D The SaveChanges carries out the database update
*********************************************************/
showlog = false;
//VERIFY
var bookWithReview = context.Books.Include(x => x.Reviews).Single();
bookWithReview.Reviews.Count.ShouldEqual(1);
}
}
public void TestCreateBookWithReview()
{
//SETUP
var options = SqliteInMemory.CreateOptions <EfCoreContext>();
using (var context = new EfCoreContext(options))
{
context.Database.EnsureCreated();
var book = new Book //#A
{ //#A
Title = "Test Book", //#A
PublishedOn = DateTime.Today, //#A
Reviews = new List <Review>() //#B
{
new Review //#C
{ //#C
NumStars = 5, //#C
Comment = "Great test book!", //#C
VoterName = "Mr U Test" //#C
}
}
};
//ATTEMPT
context.Add(book); //#D
context.SaveChanges(); //#E
/******************************************************
#A This creates the book with the title "Test Book"
#B I create a new collection of Reviews
#C I add one review, with its content
#D It uses the .Add method to add the book to the application's DbContext property, Books
#E It calls the SaveChanges() method from the application's DbContext to update the database. It finds a new Book, which has a collection containing a new Review, so it adds both of these to the database
* *****************************************************/
//VERIFY
context.Books.Count().ShouldEqual(1);
context.Set <Review>().Count().ShouldEqual(1);
}
}
public void TestDeleteBookNoRelationshipsOk()
{
//SETUP
int bookId;
var options = SqliteInMemory.CreateOptions <EfCoreContext>();
using var context = new EfCoreContext(options);
context.Database.EnsureCreated();
var bookSetup = new Book {
Title = "Test Book"
};
context.Add(bookSetup);
context.SaveChanges();
bookId = bookSetup.BookId;
context.ChangeTracker.Clear();
//ATTEMPT
var book = new Book //#A
{
BookId = bookId //#B
};
context.Remove(book); //#C
context.SaveChanges(); //#D
/*****************************************************
#A This creates the entity class that we want to delete - in this case a Book
#B This sets the primary key of the entity instance
#C The call to Remove tells EF Core you want this entity/row to be deleted
#D Then SaveChanges sends the command to the database to delete that row
****************************************************/
context.ChangeTracker.Clear();
//VERIFY
context.Books.Count().ShouldEqual(0);
}
