[hibernate-dev] Wishing to work on Hibernate's DDL capabilities

Hello everyone, During the last two weeks, I've been developing a small framework allowing to create mappings on the fly, all the while allowing existing sessions to "fail gracefully" (ie, if their session fails to find a previously mapped column or table, they try with a newer session). I don't use POJOs, so this makes it relatively easy. This means I have to do DDL on the fly. Steven Ebersole has pointed me to the Schema* classes in org.hibernate.hbm2ddl. The current abilities include adding a table, adding columns to a table and removing a table (a Configuration object with only the validated mapping of the table to drop will do the trick nicely). But the DDL capabilities are lacking: * Hibernate won't drop a column, by choice, and it currently doesn't give the user a choice because it cannot do so internally AFAICS; * it won't add indices when requested, even with hbm2ddl=update; And others. Steven has pointed to a Jira task talking about an overhaul of the Dialect abstract class and all its derivatives, because for one, the Dialect doesn't provide "purpose oriented" capabilities, just one big lump of methods. After looking at the code (3.3.1), I can see that this is the case: for instance, there's no separation between DML and DDL. I wish to help. But I'd like to know what you, seasoned Hibernate developers, would like to see. From the on, I'll put together proposals and, if one is accepted, I'll start working on it. I don't have one ready right now, the main reason for it being that I don't fully grasp the internal Hibernate architecture yet. Is there a class diagram available somewhere? Thanks, -- Francis Galiegue, fgaliegue(a)gmail.com "It seems obvious [...] that at least some 'business intelligence' tools invest so much intelligence on the business side that they have nothing left for generating SQL queries" (Stéphane Faroult, in "The Art of SQL", ISBN 0-596-00894-5)