greetings,

started moving my objects from the <timestamp> versioning to <version> versioning and discovered that in NH <version> maps to a datetime? why did we choose to implement it that way as oposed to following the Hibernate strategy of offering the version as an int?

it is conceivable that two concurrent transactions could load and update the same object at the same time. even down to the millisecond. i was hoping to use <version> to avoid this....

TIA,

-devon

IVersionType appears to be supported by Int32Type - do you have a type specified in your <version> element?

It's not just that the concurrent transactions may run at the same time. The IVersionType implementations in DateTimeType.cs and TimestampType.cs appear to just return DateTime.Now - not a great option if you have NH running on multiple hosts, or modify the db with code that uses the db server clock.

I'm probably starting to sound like a stuck record, but is there any way to use database generated row versions for concurrency checks rather than NH assigning the new value? Anyone?

Cheers,
Sam

indeed i do have version set properly:



believe it or not, i stepped away form the computer for dinner and when i returned, it was working. not sure what or why. my envirnoment has been acting flakely lately....

thanks for the post.

-devon

It do not takes version property in my mapping
========================
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0" >
<class name="MyNewBagHierarchyWork.NodeRelation,MyNewBagHierarchyWork" table="Hie_AcctRelations" >
<id name="ID" column="ID" type="Int32" unsaved-value="0">
<generator class="native" />
</id>
<property name="Weight" column="Weight" not-null="false" />
<property name="Position" column="Pos" type="Int32" insert="true" update="true" not-null="true" />
<!-- this parent is needed to avoid having "allow Nulls" in the Parent ID column in the table (Something missing in NHibernate)-->
<many-to-one name="Parent" column="ParentID" class="MyNewBagHierarchyWork.NodeBase, MyNewBagHierarchyWork" not-null="true" />
<many-to-one name="Node" column="ChildID" class="MyNewBagHierarchyWork.NodeBase, MyNewBagHierarchyWork" insert="true" update="true" cascade="all-delete-orphan" />
<version name="version" column="Version" type="Timestamp" unsaved-value="0" access="field" />

</class>
</hibernate-mapping>
====================
It gives following error

The element 'class' in namespace 'urn:nhibernate-mapping-2.0' has invalid child element 'version' in namespace 'urn:nhibernate-mapping-2.0'. List of possible elements expected: 'urn:nhibernate-mapping-2.0:property urn:nhibernate-mapping-2.0:many-to-one urn:nhibernate-mapping-2.0:one-to-one urn:nhibernate-mapping-2.0:component urn:nhibernate-mapping-2.0:dynamic-component urn:nhibernate-mapping-2.0:any urn:nhibernate-mapping-2.0:map urn:nhibernate-mapping-2.0:set urn:nhibernate-mapping-2.0:list urn:nhibernate-mapping-2.0:bag urn:nhibernate-mapping-2.0:idbag urn:nhibernate-mapping-2.0:array urn:nhibernate-mapping-2.0:primitive-array urn:nhibernate-mapping-2.0:subclass urn:nhibernate-mapping-2.0:joined-subclass'.

pcmedsinge,

the version details must be placed directly under the ID details, that is why in this case it is failing.