In jbosscmp-jdbc.xml, the <key field> is specified to indicate the primary key of the current entity used in the relationship. How does JBoss know what the foreign key is ?
For example ... a 1 to 1 relationship between UserEJB and CustomerEJB. The primary key in UserEJB table is username and I want to link this to the email column in CustomerEJB table. So tyhe customer's email will be used as their username. In jbosscmp-jdbc.xml, I only specify username in key fields. How does JBoss know to link this username to CustomerEJB' table's email column ?