nhibernate, postgresql und datetime.maxvalue

Question

Ich habe eine Anwendung, wo ich DateTime.MaxValue verwenden, um anzuzeigen, dass ein Eintrag noch nicht gelöscht wurde. Das Problem ist, dass PostgreSQL (oder npgsql oder nhibernate) 9999-12-31 23:59:59.999999 auf (10000-01-01 00:00:00) rundet, wenn das Datum/die Uhrzeit in Postgres gespeichert wird.

Das Lesen dieses Wertes aus der Datenbank führt zu InvalidCastException.

Wie kann ich Nhibernate/npgsql diese Werte lesen und sie in DateTime.MaxValue übersetzen? Es gibt andere Anwendungen, die in der Datenbank lesen/schreiben, was andere Korrekturen unmöglich macht.

* Update komplette Stack-Trace *

NHibernate.Exceptions.GenericADOException: could not load an entity: [Gate.Users.User#1][SQL: SELECT user0_.id as id15_1_, user0_.site_id as site2_15_1_, user0_.first_name as first3_15_1_, user0_.last_name as last4_15_1_, user0_.can_delete as can5_15_1_, user0_.email as email15_1_, user0_.department as department15_1_, user0_.title as title15_1_, user0_.status as status15_1_, user0_.created_at as created10_15_1_, user0_.updated_at as updated11_15_1_, user0_.timezone as timezone15_1_, user0_.middle_names as middle13_15_1_, user0_.name_prefix as name14_15_1_, user0_.name_suffix as name15_15_1_, user0_.dob as dob15_1_, user0_.removed_at as removed17_15_1_, user0_.proxy_media as proxy18_15_1_, extension1_.id as id13_0_, extension1_.site_id as site2_13_0_, extension1_.address as address13_0_, extension1_.can_delete as can4_13_0_, extension1_.forward_all as forward5_13_0_, extension1_.forward_busy as forward6_13_0_, extension1_.forward_no_answer as forward7_13_0_, extension1_.related_type as related8_13_0_, extension1_.related_id as related9_13_0_, extension1_.e164 as e10_13_0_, extension1_.outbound_e164 as outbound11_13_0_, extension1_.custom_e164 as custom12_13_0_, extension1_.removed_at as removed13_13_0_, extension1_.number_series_id as number14_13_0_, extension1_.timeout as timeout13_0_ FROM users user0_ left outer join extensions extension1_ on user0_.id=extension1_.id WHERE user0_.id=?] ---> System.InvalidCastException: Specified cast is not valid. 
    at NpgsqlTypes.NpgsqlTimeStamp.op_Implicit(NpgsqlTimeStamp timestamp) 
    at NpgsqlTypes.NpgsqlTypesHelper.<TypeInfoList>b__a(Object timestamp) 
    at NpgsqlTypes.NpgsqlBackendTypeInfo.ConvertToFrameworkType(Object providerValue) 
    at Npgsql.ForwardsOnlyDataReader.GetValue(Int32 Index) 
    at Npgsql.NpgsqlDataReader.get_Item(String name) 
    at NHibernate.Driver.NHybridDataReader.get_Item(String name) in d:\CSharp\NH\nhibernate\src\NHibernate\Driver\NHybridDataReader.cs:line 207 
    at Gate.Core.NHibernate.DateUserType.NullSafeGet(IDataReader rs, String[] names, Object owner) in C:\projects\c#\projects\MyProject\Server\Gate.Core.NHibernate\DateUserType.cs:line 39 
    at NHibernate.Type.CustomType.NullSafeGet(IDataReader rs, String[] names, ISessionImplementor session, Object owner) in d:\CSharp\NH\nhibernate\src\NHibernate\Type\CustomType.cs:line 100 
    at NHibernate.Type.AbstractType.Hydrate(IDataReader rs, String[] names, ISessionImplementor session, Object owner) in d:\CSharp\NH\nhibernate\src\NHibernate\Type\AbstractType.cs:line 131 
    at NHibernate.Persister.Entity.AbstractEntityPersister.Hydrate(IDataReader rs, Object id, Object obj, ILoadable rootLoadable, String[][] suffixedPropertyColumns, Boolean allProperties, ISessionImplementor session) in d:\CSharp\NH\nhibernate\src\NHibernate\Persister\Entity\AbstractEntityPersister.cs:line 2505 
    at NHibernate.Loader.Loader.LoadFromResultSet(IDataReader rs, Int32 i, Object obj, String instanceClass, EntityKey key, String rowIdAlias, LockMode lockMode, ILoadable rootPersister, ISessionImplementor session) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 980 
    at NHibernate.Loader.Loader.InstanceNotYetLoaded(IDataReader dr, Int32 i, ILoadable persister, EntityKey key, LockMode lockMode, String rowIdAlias, EntityKey optionalObjectKey, Object optionalObject, IList hydratedObjects, ISessionImplementor session) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 935 
    at NHibernate.Loader.Loader.GetRow(IDataReader rs, ILoadable[] persisters, EntityKey[] keys, Object optionalObject, EntityKey optionalObjectKey, LockMode[] lockModes, IList hydratedObjects, ISessionImplementor session) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 867 
    at NHibernate.Loader.Loader.GetRowFromResultSet(IDataReader resultSet, ISessionImplementor session, QueryParameters queryParameters, LockMode[] lockModeArray, EntityKey optionalObjectKey, IList hydratedObjects, EntityKey[] keys, Boolean returnProxies) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 322 
    at NHibernate.Loader.Loader.DoQuery(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 453 
    at NHibernate.Loader.Loader.DoQueryAndInitializeNonLazyCollections(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 236 
    at NHibernate.Loader.Loader.LoadEntity(ISessionImplementor session, Object id, IType identifierType, Object optionalObject, String optionalEntityName, Object optionalIdentifier, IEntityPersister persister) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 1392 
    --- End of inner exception stack trace --- 
    at NHibernate.Loader.Loader.LoadEntity(ISessionImplementor session, Object id, IType identifierType, Object optionalObject, String optionalEntityName, Object optionalIdentifier, IEntityPersister persister) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Loader.cs:line 1401 
    at NHibernate.Loader.Entity.AbstractEntityLoader.Load(ISessionImplementor session, Object id, Object optionalObject, Object optionalId) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Entity\AbstractEntityLoader.cs:line 42 
    at NHibernate.Loader.Entity.AbstractEntityLoader.Load(Object id, Object optionalObject, ISessionImplementor session) in d:\CSharp\NH\nhibernate\src\NHibernate\Loader\Entity\AbstractEntityLoader.cs:line 37 
    at NHibernate.Persister.Entity.AbstractEntityPersister.Load(Object id, Object optionalObject, LockMode lockMode, ISessionImplementor session) in d:\CSharp\NH\nhibernate\src\NHibernate\Persister\Entity\AbstractEntityPersister.cs:line 3436 
    at NHibernate.Event.Default.DefaultLoadEventListener.LoadFromDatasource(LoadEvent event, IEntityPersister persister, EntityKey keyToLoad, LoadType options) in d:\CSharp\NH\nhibernate\src\NHibernate\Event\Default\DefaultLoadEventListener.cs:line 342 
    at NHibernate.Event.Default.DefaultLoadEventListener.DoLoad(LoadEvent event, IEntityPersister persister, EntityKey keyToLoad, LoadType options) in d:\CSharp\NH\nhibernate\src\NHibernate\Event\Default\DefaultLoadEventListener.cs:line 320 
    at NHibernate.Event.Default.DefaultLoadEventListener.Load(LoadEvent event, IEntityPersister persister, EntityKey keyToLoad, LoadType options) in d:\CSharp\NH\nhibernate\src\NHibernate\Event\Default\DefaultLoadEventListener.cs:line 104 
    at NHibernate.Event.Default.DefaultLoadEventListener.ProxyOrLoad(LoadEvent event, IEntityPersister persister, EntityKey keyToLoad, LoadType options) in d:\CSharp\NH\nhibernate\src\NHibernate\Event\Default\DefaultLoadEventListener.cs:line 160 
    at NHibernate.Event.Default.DefaultLoadEventListener.OnLoad(LoadEvent event, LoadType loadType) in d:\CSharp\NH\nhibernate\src\NHibernate\Event\Default\DefaultLoadEventListener.cs:line 87 
    at NHibernate.Impl.SessionImpl.FireLoad(LoadEvent event, LoadType loadType) in d:\CSharp\NH\nhibernate\src\NHibernate\Impl\SessionImpl.cs:line 2457 
    at NHibernate.Impl.SessionImpl.Get(String entityName, Object id) in d:\CSharp\NH\nhibernate\src\NHibernate\Impl\SessionImpl.cs:line 1336 
    at NHibernate.Impl.SessionImpl.Get(Type entityClass, Object id) in d:\CSharp\NH\nhibernate\src\NHibernate\Impl\SessionImpl.cs:line 1275 
    at NHibernate.Impl.SessionImpl.Get[T](Object id) in d:\CSharp\NH\nhibernate\src\NHibernate\Impl\SessionImpl.cs:line 1259 
    at Gate.Core.NHibernate.Repository`2.<>c__DisplayClassd.<GetById>b__c() in C:\projects\c#\projects\MyProject\Server\Gate.Core.NHibernate\Repository.cs:line 151 
    at Gate.Core.NHibernate.Repository`2.ExceptionHandling[T](Func`1 action, String failedMessage) in C:\projects\c#\projects\MyProject\Server\Gate.Core.NHibernate\Repository.cs:line 46 

Answer 1

Das ist eine schlechte Idee ist. Verwenden Sie stattdessen null, es wird eine Menge Schmerzen ersparen.

Wenn Sie es immer noch tun wollen, schauen Sie in IUserType für benutzerdefinierte Handhabung von DB-Werten.

Answer 2

Wie Diego sagt, nicht verwenden Sie diese anstelle von NULL. Es ist eine sehr falsche Art, "kein Datum" zu speichern. Wenn Sie absolut keine Null haben können, ist das Hinzufügen eines zweiten Feldes, eines booleschen, ein besserer Weg.

Das heißt, sollte PostgreSQL nicht rund, so lange für Sie, dass ab, wie Sie integer Datetimes aktiviert haben:

postgres=# select '9999-12-31 23:59:59.999999'::timestamp; 
     timestamp   
---------------------------- 
9999-12-31 23:59:59.999999 
(1 row) 

Dies ist der Standard in neueren Versionen von PostgreSQL, aber wenn Sie auf einem alten bist Version kann es nicht. Um dies zu ändern, ist es leider erforderlich, dass Sie von der Quelle neu kompilieren.

(Tipp: immer auch die Version der Produkte, die Sie in der Frage verwenden, macht das wird es einfacher, um herauszufinden, was das Problem ist)