/// <summary>
/// Logs the list of BookEntities in passed context.
/// </summary>
/// <param name="context">Context containing BookEntities.</param>
private static void OutputBookEntitiesOfContext(BookEntityContext context)
{
// Select all books, ordered by descending publication date.
var query =
from book
in context.Books
orderby book.PublicationDate descending
select book;
Logging.LineSeparator("CURRENT BOOK LIST");
// Output query result (books).
Logging.Log(query);
}
/// <summary>
/// Update book page count via iteration.
/// </summary>
/// <param name="id">Book Id.</param>
/// <param name="pageCount">Book Page Count.</param>
/// <param name="context">Context containing Book to update.</param>
private static void UpdateBookPageCount(int id, int pageCount, BookEntityContext context)
{
// Find book by id.
var result = context.Books.SingleOrDefault(book => book.Id == id);
if (result == null)
{
return;
}
// Update page count.
result.PageCount = pageCount;
// Save changes to context.
context.SaveChanges();
}
private static void Main()
{
try
{
// Instantiate database context.
var context = new BookEntityContext();
// Delete database, if already exists.
Logging.LineSeparator("DELETE DATABASE");
context.Database.Delete();
// Create database.
Logging.LineSeparator("CREATE DATABASE");
context.Database.Create();
// Add some BookEntities to context.
AddBookEntityToContext(
new BookEntity(
"Magician: Apprentice",
"Raymond E. Feist",
485,
new DateTime(1982, 10, 1)),
context);
AddBookEntityToContext(
new BookEntity(
"Magician: Master",
"Raymond E. Feist",
499,
new DateTime(1982, 11, 1)),
context);
AddBookEntityToContext(
new BookEntity(
"Silverthorn",
"Raymond E. Feist",
432,
new DateTime(1985, 5, 7)),
context);
// Output BookEntities found in context.
OutputBookEntitiesOfContext(context);
UpdateBookPageCount(1, 24_601, context);
OutputBookEntitiesOfContext(context);
}
catch (EntityException exception)
{
// Output expected EntityExceptions.
Logging.Log(exception);
if (exception.InnerException != null)
{
// Output unexpected InnerExceptions.
Logging.Log(exception.InnerException, false);
}
}
catch (Exception exception)
{
// Output unexpected Exceptions.
Logging.Log(exception, false);
}
}
/// <summary>
/// Add a BookEntity to pass context and save changes.
/// </summary>
/// <param name="book">BookEntity to be added.</param>
/// <param name="context">Context to which BookEntity should be added.</param>
private static void AddBookEntityToContext(BookEntity book, BookEntityContext context)
{
context.Books.Add(book);
context.SaveChanges();
}
