auto Update timestamp field

khangharoth · **Joined:** Fri Aug 31, 2007 11:58 am **Posts:** 19

Hi , i am having a Date field which needs to be updated with current time stamp whenever any update is invoked on the row.

Its not for version control as i am handling this with another field.Its just that user needs to be aware of last update time.

so my code is somewhat like

Code:

@Version @Column( name="obj_version",nullable=false )
private int version = 0;

@Temporal( TemporalType.TIMESTAMP )
@Column( columnDefinition="Timestamp default sysdate", nullable=false )
@org.hibernate.annotations.Generated(org.hibernate.annotations.GenerationTime.ALWAYS)
private Date update_date;

this is not working ,update date is only generated at the time of insert but no further updates.

So update_date only shows creation date.

Thanks for any help.

emmanuel · **Posted:** Tue Oct 23, 2007 2:54 pm

you need some trigger in your column database.

khangharoth · **Joined:** Fri Aug 31, 2007 11:58 am **Posts:** 19

Is that means
@org.hibernate.annotations.Generated(org.hibernate.annotations.GenerationTime.ALWAYS)

works only for @Version

emmanuel · **Posted:** Mon Oct 29, 2007 4:05 pm

no it means that the value will be read from the database rather than inserted or updated.

khangharoth · **Joined:** Fri Aug 31, 2007 11:58 am **Posts:** 19

Hi ,
I am somewhat confused.

If i write a trigger in DB than what is the use of
@org.hibernate.annotations.Generated(org.hibernate.annotations.GenerationTime.ALWAYS)

Can you please point me to some example where this annotation is being used , not for version purpose i.e not with @Version.

thanks a lot.

sethrohit1977 · **Joined:** Mon Jan 22, 2007 10:32 am **Posts:** 101

As far as I know, @org.hibernate.annotations.Generated(org.hibernate.annotations.GenerationTime.ALWAYS) specifies that the property will not be inserted or updated from the object, instead it will read the value for the property from db through a subsequent select. Thats my opinion. may be I am wrong in my comprehension of things.

For updating the value in your column, you can either use a trigger (as suggested in earlier post) or you can make use of interceptor / event listener to get the job done.

HTH

emmanuel · **Posted:** Wed Oct 31, 2007 5:19 pm

sethrohit1977 wrote:

As far as I know, @org.hibernate.annotations.Generated(org.hibernate.annotations.GenerationTime.ALWAYS) specifies that the property will not be inserted or updated from the object, instead it will read the value for the property from db through a subsequent select. Thats my opinion. may be I am wrong in my comprehension of things.

You are correct, the value is generated :)