public void GetInvoiceHeaderEntityByIdFromDatabase() { IInvoice invoiceHeader = new Invoice { CustomerId = 1, SupplierId = 2, InvoiceNumber = 10 }; IInvoiceDao invoiceDao = new InvoiceDao(_sqlConnection); invoiceDao.Write(invoiceHeader); invoiceDao = new InvoiceDao(_sqlConnection); invoiceHeader = invoiceDao.GetById(invoiceHeader.Id); Assert.IsTrue(invoiceHeader != null); }