A base class for sequence manager implementations.
All sequence manager implementations need a constructor
with a PersistenceBroker argument used by the
org.apache.ojb.broker.util.sequence.SequenceManagerFactory .
author: Armin Waibel version: $Id: AbstractSequenceManager.java,v 1.17.2.3 2005/12/21 22:28:41 tomdz Exp $
Returns a unique object for the given field attribute.
The returned value takes in account the jdbc-type
and the FieldConversion.sql2java() conversion defined for field.
The returned object is unique accross all tables in the extent
of class the field belongs to.