If I try store DateTime structure into the Database then millisecond value is always 000 even if original value is for example 231, other stored values from DateTime structure are Ok.

Is This some bug in hibernate or can me somebody help with thic problem?

This happens since the resulotion of the datatime in the database is lower than the resulotion of it in .Net
In essense, the database can't save the milliseconds values.

I experience the same problem as PDu describes. I am pretty sure my problem isn't caused by database resolution being low, since I am using the timestamp type in Oracle 10g which to my knowledge has 6 digits for milliseconds.

I have also tried using regular ADO.NET to read/write datetime instances to the database. This yielded the expected result, where the milleseconds would be persisted and read back.

Any other ideas?

It may be due to the fact that DateTime.ToString() don't include the milliseconds...

You should map the column using type="timestamp", this will tell NHibernate to use the maximum possible precision.

Sergey,

I have defined the following mapping:

<timestamp name="Timestamp" column="`TIME_STAMP`"/>

But using Oracle 10G Express Edition the millisecond is always 000.

Is there a way to fix this issue?

Thanks.

Hi!
I agree with KPixel:


I think the offending code is in : src\NHibernate\Type\DateTimeType.cs (or if you prefer in TimestampType.cs)

In the method:



IMHO it should be something like (but I haven't tested it):



The trick i think, is in the ".fff". I have had this problem with other object relational mappers... its a slight, but pretty common mistake.

I am also a little worried about this... what happens if my particular database doesn't like the default implementation of ObjectToSQLString ? Do I have to create a pariticular NHibernateType? (Or... Is there a way to override it in a central location? (perhaps in Driver or Dialect?))

AFAIK the DateTime.ToString() is "culture dependant" that is it generates the string representation in a "based on the current culture", so I think there could be problems if the culture in the application server or in the smartclient is different than the one in the database server (for example if the user plays with his particular computer configuration... and changes the order of the the date, form year/month/day to year/day/month the 2 of March could become the 3 of February)

So... IMHO all the DateTime related types should generate SQL represetantion (inside ObjectToSQLString) using a fixed format string, so that the result is always the same (regardless of the culture)... what do you think?

ObjectToSQLString and DateTime.ToString() are only used when inserting literal values into SQL (for example, when using literal values instead of parameters in HQL). If you use parameters, the database driver formats the value.

As to why the timestamp's milliseconds are set to 000, it looks like it's some Oracle-related problem - maybe your column is actually set to only have up to second precision, or something like that.

From Oracle, I can run this query: UPDATE HOSTS SET TIME_STAMP = SYSTIMESTAMP;

TIME_STAMP field gets correctly updated with milliseconds.

So I'm not sure it an Oracle problem.

Here is the mapping:
<?xml version="1.0" encoding="utf-8" ?>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">

<class name="Eforce.DOCSRunner.Component.Modules.Host,DOCSRunner.Component.Implement" table="HOSTS">
<cache usage="read-write"/>
<id name="Id" column="ID" type="Int32" unsaved-value="0">
<generator class="native">
<param name="sequence">HOSTS_GENERATOR</param>
</generator>
</id>
<timestamp name="Timestamp" column="`TIME_STAMP`"/>
<property name="Name" column="`NAME`" type="String" length="50" />
<property name="Port" column="`PORT`" type="Int32"/>
<property name="Address" column="`ADDRESS`" type="String" length="50" />
<property name="ProgIdPackager" column="`PROG_ID_PACKAGER`" type="String" length="50" />
<property name="ProgIdExecutor" column="`PROG_ID_EXECUTOR`" type="String" length="50" />
<property name="Service" column="`SERVICE`" type="String" length="50" />
<many-to-one name="Module" column="`MODULE`" class="Eforce.DOCSRunner.Component.Modules.Module,DOCSRunner.Component.Implement" cascade="none"/>
<property name="Disabled" column="`DISABLED`" type="Boolean" />
</class>

</hibernate-mapping>


Here is the log from NHibernate:
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Impl.BatcherImpl - Building an IDbCommand object for the SqlString: INSERT INTO HOSTS ("PROG_ID_EXECUTOR", "TIME_STAMP", "PROG_ID_PACKAGER", "PORT", "DISABLED", "ADDRESS", "NAME", "SERVICE", "MODULE", ID) VALUES (:"PROG_ID_EXECUTOR", :"TIME_STAMP", :"PROG_ID_PACKAGER", :"PORT", :"DISABLED", :"ADDRESS", :"NAME", :"SERVICE", :"MODULE", :ID)
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Persister.EntityPersister - Dehydrating entity: [Eforce.DOCSRunner.Component.Modules.Host#2]
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.StringType - binding null to parameter: 0
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.TimestampType - binding '9:15 AM' to parameter: 1
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.StringType - binding null to parameter: 2
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.Int32Type - binding '8203' to parameter: 3
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.BooleanType - binding 'False' to parameter: 4
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.StringType - binding 'HTTP://SKIPPER-MASTER:8203/DBSynchro' to parameter: 5
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.StringType - binding 'SKIPPER-MASTER' to parameter: 6
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.StringType - binding 'JobDBSynchro' to parameter: 7
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.Int32Type - binding '2' to parameter: 8
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Type.Int32Type - binding '2' to parameter: 9
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - INSERT INTO HOSTS ("PROG_ID_EXECUTOR", "TIME_STAMP", "PROG_ID_PACKAGER", "PORT", "DISABLED", "ADDRESS", "NAME", "SERVICE", "MODULE", ID) VALUES (:p0, :p1, :p2, :p3, :p4, :p5, :p6, :p7, :p8, :p9)
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p0 = ''
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p1 = '5/14/2006 9:15:02 AM'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p2 = ''
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p3 = '8203'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p4 = 'False'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p5 = 'HTTP://SKIPPER-MASTER:8203/DBSynchro'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p6 = 'SKIPPER-MASTER'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p7 = 'JobDBSynchro'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p8 = '2'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.SQL - :p9 = '2'
2006-05-14 09:15:02,071 [4920] DEBUG NHibernate.Impl.BatcherImpl - Closed IDbCommand, open IDbCommands :0

I have also tested with second cache level disabled.

Thanks.

Hi!
Maybe:
http://msdn.microsoft.com/library/defau ... access.asp
Can help you locate the source of the error... it even has a section named "Using Tracing to Debug a Parameter Binding Problem"

I think I can help out here: Don't use Microsoft's / .Net's standard Oracle provider.
Since switching to Oracle's ODPNet driver, I'm successfully saving and retrieving the milliseconds....
(Once you've got a suitable Oracle client installed,
a) change your hibernate.connection.driver_class to NHibernate.Driver.OracleDataClientDriver instead of NHibernate.Driver.OracleClientDriver, and
b) swap the "server" in the connection string for a "Data Source" specifying the SID.)

Hope that cleans this up (for future Googlers)!
Mike.