Hi , i was hitting this exception


Supposed i have this table called AUDIT TABLE and created a POJO for this using increment generator


Every Success Operation i will insert to this table

The Problem is , hibernate cache the max id when the application starts
and just increment the value when there is inserting to this table.


Lets say when application start my data in my table such as below
ID Name
1 logout
2 login
3 delete


Then i start my application. and perform maybe 2 operation
so the new state of the table will be something as below
ID Name
1 logout
2 login
3 delete
4 some operation
5 some operation

then here it goes the bad scenario
i manually insert with ID = 6 and Name = Test using DB console

After this , any operation i do will give me unique constraint exception.

Because Hibernate cache the max id when the application starts so it dont always fetch from database.

Any workaround / configuration to be made if i still want to user increment generator to always fetch the max value in the DB??


Or is it better to use sequence in cluster environment??

I think this answers your question.

http://www.hibernate.org/hib_docs/v3/re ... -generator

increment

generates identifiers of type long, short or int that are unique only when no other process is inserting data into the same table. Do not use in a cluster



If you database is supported by the identity generator then it's really easy to switch to it. In mysql just alter the field to autoincrement.

Good luck!

Marius