Giulio Cesare Solaroli <slrgcs..bn-italy.com> wrote:
> In EOF we have written a few qualifiers (in Cayenne they are called
> expressions, if I get it right) like:
> - empty relationship;
> - not empty relationship;
> - match all values;
> - no match for value;
Take a look at
http://www.objectstyle.org/cayenne/userguide/expressions/shortcut.html
and the rest of chapter 11. I think some of what you're looking for is in
there.
> Plus, we have extended the editing context to implement a few method to:
> - return the number of records/objects matching a given
> qualifier/expression (select count(*));
> - return if a given expression matches any value (select dummy from
> dual where exists(...); similar to a select count(*) checking if the
> result is greater than zero, but much more efficient, as it returs as
> soon as it finds a match).
I don't know the answer to this, but I would guess the Expression class or
one of the others in the exp package. Your extensions sound like useful
additions to Expression providing you can implement them in a database
independent way (the second one sounds a little tricky and looks
Oracle-specific).
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