nhibernate, postgresql and datetime.maxvalue
-
11-10-2019 - |
Question
I got a application where I use DateTime.MaxValue
to indicate that a entry have not been deleted yet. The problem is that PostgreSQL (or npgsql or nhibernate) rounds 9999-12-31 23:59:59.999999
to (10000-01-01 00:00:00
) when the date/time is stored in postgres.
Reading that value back from the database results in a InvalidCastException
.
How can I make nhibernate/npgsql read those values and translate them to DateTime.MaxValue
?
There are other applications reading/writing to the database, which makes any other fixes impossible.
*Update, Complete 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
Solution
That's a bad idea. Use null instead, it'll save a lot of pain.
If you still want to do it, look into IUserType
for custom handling of DB values.
OTHER TIPS
As Diego says, don't use this instead of NULL. It's a very wrong way to store "no date". If you absolutely can't have null, adding a second field, a boolean, is a better way.
That said, PostgreSQL shouldn't round that off for you as long as you have integer datetimes enabled:
postgres=# select '9999-12-31 23:59:59.999999'::timestamp;
timestamp
----------------------------
9999-12-31 23:59:59.999999
(1 row)
This is the default in newer versions of PostgreSQL, but if you're on an old version it may not. Unfortunately, changing that requires recompiling from source.
(tip:always include the version of the products you're using in the question, that'll make it easier to figure out what the problem is)