public void Delete()
{
using (testEntities context = new testEntities())
{
foreach (Book b in context.Books)
context.DeleteObject(b);
context.SaveChanges();
}
MySqlDataAdapter da = new MySqlDataAdapter("SELECT * FROM Books", conn);
DataTable dt = new DataTable();
da.Fill(dt);
Assert.AreEqual(0, dt.Rows.Count);
}