concurrent transactions

[Jasvir Rupana]

hello everyone,
please some one clear my following doubt in concurrent transactions situation



1. 2 users open same database row to update ,say user 1 update a field RED and after a moment other user updates it to GREEN. user 1 changes will be lost .how to handle it in simple JDBC /hibernate .

i have read isolation levels dirty reads and all therotically but coldnot find some practical soultion.

i read that hibernatea appends some uid with each row to handle this but never saw this happening.

whats the solutions guys in jdbc and hibernate ??

[Paul Sturrock]

Lost updates can be prevented by implementing optimistic locking. If its Hibernate you are using, I'd first google the term, then check out its documentation on versioning.