How to set version timestamp with sysdate from database

tahcow · **Joined:** Thu Feb 26, 2004 12:45 pm **Posts:** 2

Hi,
I anm using <version type='timestamp' column='lastMod' />
how could i set the lastMod column on insert and update with the time of my database server instead of the time of my appserver.

Thanks in advance
Thierry

shl · **Posted:** Thu Feb 26, 2004 1:38 pm

Hi Thierry!

tahcow wrote:

how could i set the lastMod column on insert and update with the time of my database server instead of the time of my appserver.

I don't think it is a good idea to set version timestamp manually. As I got version is a utility field that is needed for optimistic locking and updating objects with composite-id. So let hibernate set it himself (it uses application server timestamp). As rule I use field access to all my versions and don't have setters for them for avoiding troubles.

If you need business timestamp field with database timestamp, introduce it and use SQL trigger or set it's default value to 'SYSTEM_DATE', 'CURRENT_TIMESTAMP' via SQL default clause of CREATE TABLE.

tahcow · **Joined:** Thu Feb 26, 2004 12:45 pm **Posts:** 2

The problem is when using a trigger on the database, the lastmod column value set by hibernate on update or insert is overwritten by the trigger which is executed after.
So the object become stale(if the time on both servers is not synchronize)
I know i can do a session.refresh(Object) after my update/save action but this is an extra select.

Thats why i want to find a way to tell hibernate to set the lastmod column value with the sysdate of the database. Can this be done ?

TIA
Thierry

shl · **Posted:** Thu Feb 26, 2004 4:15 pm

version timestamp is an internal hibernate column/property, you should not change it either via trigger or manually. For business needs introduce another timestamp field and set it manually or via trigger, don't combine version timestamp and business timestamp property.

emmanuel · **Posted:** Mon Mar 01, 2004 11:39 am

I would recommand version as an long usage.
getter / setter for version is needed in case of detach objects usage.

shl · **Posted:** Tue Mar 02, 2004 3:46 am

I think public setter for version is not a good idea.
When I need to set version in some tricky cases I use factorty method or copy constructor with addition version parameter.

Code:

public MyCalss(MyClass that, int version)
{
    if (null == that)
        throw new NullPointerException();

    if (version <= that.version)
        throw new IllegalArgumentException();

    this.memeber1 = that.memeber1;
    ...
    this.version = version;
}

emmanuel · **Posted:** Wed Mar 03, 2004 6:41 pm

Can't do that with struts and it's JavaBean form