For a registration module not all userNames are allowed. So we filled a database table (BlockedValues) with all kinds of strings that are not allowed as username (assh,dick,motherf etc etc.)

But I don't know how to create such an expression..
The following is just the 'wrong way around':

Criteria criteria = session.createCriteria(BlockedValues.class,"BV");
criteria.add(Expression.like("blockedValue","%"+userName + "%"));

Thanks

Niels