Outer Join logic

Question

The following code is an example of how to perform an outer join, in this case with ReportQuery (thanks Doug):
        ExpressionBuilder eb = new ExpressionBuilder();
        ReportQuery rq = new ReportQuery(Employee.class, eb);
        rq.addAttribute("firstName");
        rq.addAttribute("lastName");
        rq.addAttribute("areaCode", eb.anyOfAllowingNone("phoneNumbers").get("areaCode"));
        List<ReportQueryResult> results =  (List<ReportQueryResult>) session.executeQuery(rq);My question is about the logic Toplink uses to generate the outer join statement with the "(+)" in the generated sql.
Does Toplink only generate the join statement if the same attribute is chosen in the select statement (in the above example "areaCode")?
Along the same line of questioning, does it matter which attribute was in the get() call? So, in the above example did it have to be areaCode, or could it have been any other attribute of phoneNumber, and it still would have performed the join?
In my case, because the selection attributes are built up dynamicly, should I add all attributes of my child class (my equivalent PhoneNumber class)?

Answer 1

Thanks for your reply Doug.
One last question, hopefully.
I have a parent table with 2 child tables. When attempting an outer join with both, toplink does not attempt to outer join either. I understand why, sort of - as you get an error when attempting this in sqlplus with "(+)" syntax.
I understand that you can outer join > 1 other table to a parent with ansi sql syntax:
    select dept.*,emp.*
    from dept left outer join emp
    on dept.deptno = emp.deptnoWill toplink allow > 1 child table outer join to a parent table?