nHibernate and concurrency check

Question

I want to achieve concurrency check using nHibernate 3 using UnitOfWork pattern.

To be more precise:

• open new session session,
• load entity in a session,
• close session,
• give user some time to edit data in loaded entity,
• open new session,
• update data
• close session.

I'm using timestap to version entity.

Here is my mapping file

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
                   assembly="...."
                   namespace="...."
                   default-lazy="false">    
  <class name="Employee"
         optimistic-lock="version"
               dynamic-update="true">
    <id name="Id">
      <generator class="native" />
    </id>
    <version column="LastEditDate" generated="always" type="timestamp" />
    <property name="Name" not-null="1" length="255" />
    <property name="LastEditUser" not-null="1" length="255"/>
  </class>    
</hibernate-mapping>

I have no idea how to update entity in session context

var entity = <updated by user>
using (var session = GetNewSession())
{
    //todo: load current version value / attach entity to context
    session.SaveOrUpdate(entity);
    //if concurency check fails, StaleObjectException (or similar) is expected to be thrown
}

In SQL it should work like this

UPDATE ENTITY SET LastEditDate = @P1, ... WHERE ID = @P2 AND LastEditDate = @P3

where:
@P1 - new LastEditDate
@P2 - entity ID
@P3 - previous LastEditDate

If ROWSMODIFIED = 1 then update was successfull, else if = 0 then ConcurrencyException

Using Linq2Sql it was very simple: create versioning column, attach entity to new session context and try to update.

How can I do it in nHiberate? Is it supported?

Answer 1

session.Update(entity)

应该足够了。

Answer 2

我认为您应该使用session.Lock(entity,LockMode.Update) 。