i need to add a unique index to my db like this:

CREATE UNIQUE INDEX d_7col_uni_idx ON m.dv 

(fk_id, name, coalesce(make,'~~~NULL~~~'), coalesce(model,'~~~NULL~~~')

, coalesce(type,'~~~NULL~~~'), coalesce(cbo_id,-1), coalesce(pt,'~~~NULL~~~'))

WHERE expiration_date IS NULL;

i'm using hbm2java to generate my java classes from the db by providing a reveng.xml file to help. adding this constraint causes the generated java code to have :

@Table(name="dv"

, uniqueConstraints = @UniqueConstraint(columnNames={"fk_id", "name", "(COALESCE(make, '~~~NULL~~~'::character varying))", "(COALESCE(model, '~~~NULL~~~'::character varying))", "(COALESCE(type, '~~~NULL~~~'::character varying))", "(COALESCE((cbo_id)::integer, (-1)))", "(COALESCE(pt, '~~~NULL~~~'::character varying))"}) 

)

When running my unit tests, I get an exception:

java.lang.NullPointerException

at org.hibernate.mapping.Constraint$ColumnComparator.compare(Constraint.java:134)

My quick thought is to just get hibernate/hbm2java to ignore that constraint and not have that annotation on the generated class. is this possible? can i specify that the unique index should be skipped?