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In hibernate how do I always use db server's timestamp?

Answer 1

+1 A:

This isn't a pretty solution but it works. Use the formula property.

<property name='ServerDate' formula='getdate()'/>

Place that field in some kind of dummy entity and you'll be able to pull the date from your SQL database and from there you can assign it to your last_update column.

I've done quite a bit of searching and I haven't found an easier way to do this.

Spencer Ruport 2010-03-16 16:15:21

Thanks for your answer, does it mean that I can't have ServerDate as one of the property for object being saved and I have to use dummy entity?

Vishal 2010-03-16 17:00:43

You can but you'll still have to assign it. I only recommended the dummy entity because it could be misleading to have that field as a property of a real entity.

Spencer Ruport 2010-03-16 17:27:25

Ok, I am new to hibernate do I have to create configuration file for that dummy entity? How do I get ServerDate and later assign it back to last_update field?

Vishal 2010-03-16 18:14:58

Yes create a configuration file like you normally would. Point it to some arbitrary table and do all the normal work you'd do to retrieve an instance. Once you have the object this property will be populated with the SQL server's date and you can assign it to the last_update property of the entity you're working with.

Spencer Ruport 2010-03-16 18:55:35

Can't we get the db date from the hibernate-sql and use it?

Vishal 2010-03-16 19:07:31

Answer 2

A:

You can create a new SaveOrUpdateEventListener:

public class DateTimeSaveOrUpdateEventListener : DefaultSaveOrUpdateEventListener
{
    protected override object EntityIsPersistent(SaveOrUpdateEvent @event)
    {
        MyEntity ent = @event.Entity as MyEntity;
        if(ent != null)
            ent.LastUpdate = DateTime.Now;
        return base.EntityIsPersistent(@event);
    }

    protected override object EntityIsTransient(SaveOrUpdateEvent @event)
    {
        MyEntity ent = @event.Entity as MyEntity;
        if(ent != null)
            ent.LastUpdate = DateTime.Now;
        return base.EntityIsTransient(@event);
    }
}

and register it in your configuration like this:

var listener = new DateTimeSaveOrUpdateEventListener();
config.SetListener(NHibernate.Event.ListenerType.SaveUpdate, listener);
config.SetListener(NHibernate.Event.ListenerType.Save, listener);

snicker 2010-03-16 16:29:38

Answer 3

A:

I used HQL and it worked

entity.setLastUpdate((Date) session.createSQLQuery(
        "select getdate()").list().get(0))

Vishal 2010-03-16 21:34:11

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In hibernate how do I always use db server's timestamp?

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