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POnHibernate eager loading- strange update behaviour
 

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  1. POnHibernate eager loading- strange update behaviour
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    <p>my domain is an airport, which contains several terminals, and each terminal contains zones etc.<br> since the number of airport / terminal / zone entities is very small, i'd like to:<br> 1. load all the heirarchy eagerly when retrieving an airport.<br> (using the following fluent configuration:<br></p> <pre><code>//eagerly load terminals mapping.HasMany(x =&gt; x.Terminals).Not.LazyLoad() .Cache.ReadWrite(); </code></pre> <p>)<br> 2. enable 2nd level caching, so that all retrievals of an airport object would not hit the DB.<br> <br> the eager loading and caching works fine, but the following test produces some strange behaviour.<br> (the following code retrieves an airport entity twice (not hitting the DB the second time), and updates one of them.)<br></p> <pre><code> [TestMethod] public void TestSecondLevelCache() { Airport firstAirport = null, secondAirport = null; Console.WriteLine("first select"); using (ISession session = this.SessionFactory.OpenSession()) { using (ITransaction transaction = session.BeginTransaction()) { //the idea here is to see whether there are two calls to DB here. check the sql output AirportDAO dao = new AirportDAO(session); firstAirport = dao.GetAirport(); transaction.Commit(); } } Console.WriteLine("second select"); using (ISession session = this.SessionFactory.OpenSession()) { using (ITransaction transaction = session.BeginTransaction()) { //the idea here is to see whether there are two calls to DB here. check the sql output AirportDAO dao = new AirportDAO(session); secondAirport = dao.GetAirport(); transaction.Commit(); } } Console.WriteLine("Are those the same airport instance? " + firstAirport.Equals(secondAirport)); Console.WriteLine("now adding a terminal"); using (ISession session = this.SessionFactory.OpenSession()) { using (ITransaction transaction = session.BeginTransaction()) { secondAirport.Terminals.Add(new Terminal() { Name = "terminal added to second airport", Zones = new List&lt;Zone&gt;() }); session.Update(secondAirport); transaction.Commit(); } } //this Assert fails, since firstAirport != secondAirport Assert.IsNotNull(firstAirport.Terminals.FirstOrDefault(t =&gt; t.Name.Contains("second airport"))); } </code></pre> <p>see the resulting output:<br></p> <blockquote> <p>first select<br> NHibernate: SELECT airport0_.Id as Id36_0_, airport0_.Name as Name36_0_, airport0_.IsDeleted as IsDeleted36_0_ FROM dbo.[Airport] airport0_ WHERE airport0_.Id=@p0;@p0 = 1<br><br> NHibernate: SELECT terminals0_.Airport_id as Airport4_1_, terminals0_.Id as Id1_, terminals0_.Id as Id50_0_, terminals0_.Name as Name50_0_, terminals0_.IsDeleted as IsDeleted50_0_, terminals0_.Airport_id as Airport4_50_0_ FROM dbo.[Terminal] terminals0_ WHERE terminals0_.Airport_id=@p0;@p0 = 1<br><br> NHibernate: SELECT zones0_.Terminal_id as Terminal4_1_, zones0_.Id as Id1_, zones0_.Id as Id51_0_, zones0_.Name as Name51_0_, zones0_.IsDeleted as IsDeleted51_0_, zones0_.Terminal_id as Terminal4_51_0_ FROM dbo.[Zone] zones0_ WHERE zones0_.Terminal_id=@p0;@p0 = 2<br><br> <br> second select<br> Are those the same airport instance? False<br> <br> now adding a terminal<br> NHibernate: select next_hi from dbo._uniqueKey with (updlock, rowlock)<br> NHibernate: update dbo._uniqueKey set next_hi = @p0 where next_hi = @p1;@p0 = 17, @p1 = 16<br><br> NHibernate: INSERT INTO dbo.[Terminal] (Name, IsDeleted, Airport_id, Id) VALUES (@p0, @p1, @p2, @p3);@p0 = 'terminal added to second airport', @p1 = False, @p2 = NULL, @p3 = 16<br> NHibernate: UPDATE dbo.[Airport] SET Name = @p0, IsDeleted = @p1 WHERE Id = @p2;@p0 = 'test airport', @p1 = False, @p2 = 1<br><br> NHibernate: UPDATE dbo.[Terminal] SET Name = @p0, IsDeleted = @p1, Airport_id = @p2 WHERE Id = @p3;@p0 = 'test terminal', @p1 = False, @p2 = 1, @p3 = 2<br><br> NHibernate: UPDATE dbo.[Zone] SET Name = @p0, IsDeleted = @p1, Terminal_id = @p2 WHERE Id = @p3;@p0 = 'test zone', @p1 = False, @p2 = 2, @p3 = 3<br><br> NHibernate: UPDATE dbo.[Terminal] SET Airport_id = @p0 WHERE Id = @p1;@p0 = 1, @p1 = 16<br> <br><br> </blockquote> <p><br>my problems are:<br> 1. the strange update behaviour which updates everything...<br> 2. the fact that firstAirport and secondAirport are not the same object (maybe I'm missing something about 2nd level cache?)<br><br> thanks in advance,<br> Jhonny</p> </p>
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