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The moose likes EJB Certification (SCBCD/OCPJBCD) and the fly likes HF Page434 Q. 12 Big Moose Saloon
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HF Page434 Q. 12

Purvesh Vora
Ranch Hand

Joined: Dec 10, 2003
Posts: 47
Hi Friends,
The Q.12 is
Given CMP beans CustomerBean, OrderBean and LineItemsBean with the following relationships:

CustomerBean (1) <--> OrderBean (n)
OrderBean(1) <--> LineItemsBean(n)

Which will return all orders that have line items? (Choose all that apply.)
A. SELECT DISTINCT o FROM Order o, IN (o.lineItems)li
B. SELECT DISTINCT OBJECT(O) FROM Order o, IN(o.lineItems) li
C. SELECT OBJECT(o) FROM Order o WHERE o.lineItems = 0

The correct answers are listed as B and D.

B is fine. But how the answer D is TRUE?

Could anybody please explain?

Regards,<br />Purvesh<br />SCJP, SCBCD, IBM Exam #486
Kin Ng

Joined: May 06, 2005
Posts: 16
I think it's the wording of the question.
It says "will return all orders that have line items" (didn't say only).

The set "all orders that have line items" is definitely
a subset of the resultset of Query D, which contains all orders.
That's why D is correct too.

This is what I think.
David McDonagh

Joined: Feb 13, 2004
Posts: 19
Actually can someone explain why Option B is correct? My naive understanding that the syntax DISTINCT would only return one object and not a collection i.e. "all orders with lineitems".
Sumitro Palit
Ranch Hand

Joined: Dec 13, 2003
Posts: 37
DISTINCT implies duplicates will be avoided - it can still return a collection of unique records staisfying the QL statement.
I agree. Here's the link:
subject: HF Page434 Q. 12
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