private static void TestRelatedBooksExtendedFunctionality(BookShopSystemEntities context)
{
var books = context.Books.Take(3).ToList();
books[0].RelatedBooks.Add(books[1]);
books[1].RelatedBooks.Add(books[0]);
books[0].RelatedBooks.Add(books[2]);
books[2].RelatedBooks.Add(books[0]);
context.SaveChanges();
var booksFromQuery = context.Books
.Take(3)
.Select(b => new
{
b.Title,
b.RelatedBooks
});
foreach (var book in booksFromQuery)
{
Console.WriteLine("--{0}", book.Title);
foreach (var relatedBook in book.RelatedBooks)
{
Console.WriteLine(relatedBook.Title);
}
}
}
private static void GetBooksOfGeorgePowell(BookShopSystemEntities context)
{
var georgePowellsBooks = context.Books
.Where(b => b.Author.FirstName == "George" && b.Author.LastName == "Powell")
.OrderBy(b => b.ReleaseDate)
.ThenBy(b => b.Title)
.Select(b => new
{
b.Title,
b.ReleaseDate,
b.Copies
});
}
private static void GetCategoriesSortedByCountOfBooks(BookShopSystemEntities context)
{
var latest3BooksFromEachCategory = context.Categories
.OrderByDescending(c => c.Books.Count)
.Select(c => new
{
Category = c.Name,
BooksCount = c.Books.Count,
Books = c.Books
.OrderByDescending(b => b.ReleaseDate)
.Take(3)
.Select(b => new
{
b.Title,
b.ReleaseDate
})
});
}
public static void Main()
{
var context = new BookShopSystemEntities();
// 1
GetBooksWithReleaseYearAfter2000(context);
// 2
GetAuthorsWithABookAfter1990(context);
// 3
GetAuthorsSortedByNumberOfBooks(context);
// 4
GetBooksOfGeorgePowell(context);
// 5
GetCategoriesSortedByCountOfBooks(context);
TestRelatedBooksExtendedFunctionality(context);
}
private static void GetAuthorsSortedByNumberOfBooks(BookShopSystemEntities context)
{
var authorsSortedByBooksCount = context.Authors
.OrderByDescending(a => a.Books.Count)
.Select(a => new
{
a.FirstName,
a.LastName,
BooksCount = a.Books.Count
});
}
private static void GetBooksWithReleaseYearAfter2000(BookShopSystemEntities context)
{
var booksWithReleaseYearAfter2000 = context.Books
.Where(b => b.ReleaseDate.Value.Year > 2000)
.Select(b => b.Title);
}
private static void GetAuthorsWithABookAfter1990(BookShopSystemEntities context)
{
var authorsWithABookAfter1990 = context.Authors
.Where(a => a.Books.Count(b => b.ReleaseDate.Value.Year < 1990) >= 1)
.Select(a => new
{
a.FirstName,
a.LastName,
BookCount = a.Books.Count(b => b.ReleaseDate.Value.Year < 1990)
});
}
