NHibernate 5 now support the pattern https://enterprisecraftsmanship.com/posts/nhibernate-async-support/ https://nhibernate.info/doc/nhibernate-reference/transactions.html https://bartwullems.blogspot.com/2017/12/nhibernate-5asyncawait.html https://codereview.stackexchange.com/questions/257665/how-to-make-a-good-session-handling-with-nhibernate ISessionFactory sessions; ISession session = sessions.OpenSession(); ITransaction tx = null; try { tx = session.BeginTransaction()) Customer customer = await session.GetAsync(1); List customers = await session.Query().ToListAsync(); Customer customer = await session.Query() .Where(x => x.Name.Contains("Customer 1")) .SingleOrDefaultAsync(); session.Save(customer); tx.Commit(); } catch (Exception) { if (tx != null) tx.Rollback(); session.Close(); throw; } finally { session.disconnect(); } Using async repository ---------------- public class ContractsController : ControllerBase { private readonly BaseRepository contractRepository; public ContractsController(BaseRepository contractRepository) { this.contractRepository = contractRepository; } public async Task Get([FromODataUri] int key) { var contract = await contractRepository.FindOneAsync(key); if (contract == null) { return StatusCode(HttpStatusCode.NotFound); } return Ok(contract); } } Repository Impl (generic) ----------------- public class BaseRepository : IRepository where T : class { protected ISession session = HttpContext.Current.Items["nhibernate.current_session"] as ISession; protected ITransaction transaction = null; public BaseRepository() { //session = NHibernateHelper.OpenSession(); transaction = session.BeginTransaction(); } public async void Create(T entity) { await session.SaveOrUpdateAsync(entity); await transaction.CommitAsync(); } public async void DeleteAsync(TId key) { var entity = await session.LoadAsync(key); await session.DeleteAsync(entity); await transaction.CommitAsync(); } public async Task> FindAllAsync() { return await session.Query().ToListAsync(); } public async Task FindOneAsync(TId key) { return await session.GetAsync(key); } public async void UpdateAsync(T entity) { await session.SaveOrUpdateAsync(entity); await transaction.CommitAsync(); } } Getting Data async ----------------- Customer customer = await session.GetAsync(1); List customers = await session.Query().ToListAsync(); Customer customer = await session.Query() .Where(x => x.Name.Contains("Customer 1")) .SingleOrDefaultAsync(); Creating/Updating Data async ------------------ using (ISession session = sessionFactory.OpenSession()) using (ITransaction transaction = session.BeginTransaction()) { Customer customer = await session.GetAsync(1); customer.Name = "Customer 3"; await session.SaveOrUpdateAsync(customer); await transaction.CommitAsync(); } nhibernate 5 feature ----------------- private ISession _session; public async Task GetAsync(int id) where T : ISomeEntity { return await _session.GetAsync(id); } other simple ways ----------------- NHibernate 5–Async/await The introduction of async/await to optimize IO bound methods/operations. // Usage ICriteria.ListAsync() var customers = await session .CreateCriteria() .ListAsync(); // Usage ICriteria.UniqueResultAsync() var customer = await session .CreateCriteria() .Add(Restrictions.Eq("Name", "Ayende")) .UniqueResultAsync(); // Usage IQueryOver.ListAsync() var person = await session .QueryOver() .ListAsync(); // Usage IQueryOver.ListAsync() var person = await session .QueryOver() .Select(p => p.Name) .ListAsync(); // Usage IQueryOver.SingleOrDefaultAsync() var customer = await session .QueryOver() .SingleOrDefaultAsync(); //Usage of ISession.FlushAsync() _session.FlushAsync(cancellationToken);

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