nHibernate and concurrency check
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-mapp开发者_如何学运维ing-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?
session.Update(entity)
should be enough.
I think you should use session.Lock(entity,LockMode.Update)
.
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