><a href="../../jakarta/persistence/TransactionRequiredException.html" title="class in jakarta.persistence">TransactionRequiredException</a></code> - if a lock mode other than
         <code>NONE</code> has been set and there is no transaction
         or the persistence context has not been joined to the transaction</dd>
<dd><code><a href="../../jakarta/persistence/PessimisticLockException.html" title="class in jakarta.persistence">PessimisticLockException</a></code> - if pessimistic locking
         fails