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From Matthew Adams <matt...@matthewadams.org>
Subject #key and #value in query filter?
Date Tue, 30 Oct 2007 18:09:27 GMT
Hi all,

I just proposed in JPA on the thread for support for Maps that JPAQL  
support "#key" and "#value" for navigation through maps, much like we  
can use "#key" and "#value" to define fetch groups in JDO.  I took  
for granted that these expressions can be used in JDOQL, and after a  
search through the spec, I don't see where they can.  I only see the  
list of supported Map and Collection methods in 14.6.2, "Filter  
specfication".

One of the JPA examples in the proposal looks like the following:

SELECT im#value
FROM Item i JOIN i.images im
WHERE im#key in ('thumbnail', 'full', 'high-res')

First, what would the equivalent JDOQL for this be?

Second, what are your thoughts on JDOQL support for "#key", "#value"  
and "in"?  This would allow us to write the following.  This is  
decidedly not very Java-like (a design goal of JDOQL), so this would  
be a bit of a departure from tradition for JDOQL.

-matthew

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