Creating a composite/concatenated unique key

[dana n]

How do I create a composite/concatenated unique key in EA? While checking Primary Key in various fields, in the end, creates a composite PK, checking > 1 field for Unique only creates separate, single-field unique keys.

How can I specify, and thus automatically create, a composite unique key without having to remember to hand-edit the generated DDL later (removing the multiple Unique keys and adding all fields to a single unique key SQL statement).

Thanks.

Dana