Re: [jira] Updated: (CAY-1282) Use #result as optional directive for only few columns (not all)

From: Robert Zeigler (robert.zeigle..uregumption.com)
Date: Fri Oct 16 2009 - 13:57:55 EDT

  • Next message: Andrus Adamchik: "Re: [jira] Updated: (CAY-1282) Use #result as optional directive for only few columns (not all)"

    +1.

    Although having truly generified queries would be useful in many
    situations, I think it's too late in the dev. cycle for 3.0 to add
    this now.

    Robert

    On Oct 16, 2009, at 10/1612:55 PM , Andrus Adamchik wrote:

    >
    > On Oct 16, 2009, at 8:04 PM, Andrey Razumovsky wrote:
    >
    >> Actually, as already mentioned, we need to do something around
    >> CAY-942
    >> (query generics). This is very critical and desired API change
    >
    > Not sure if we have another more precise Jira (since generics in
    > relationships mentioned in this Jira have already been added).
    >
    > Anyways, if we are talking about query generics, I did some research
    > and prototyping of that in the past. My conclusion is that to do it
    > right it has to be a rather dramatic change in Cayenne, affecting
    > not simply the code, but a number design concepts. Essentially we
    > have too many variables to squeeze into a rather rigid Java generics
    > engine. To start, here is possible query result types:
    >
    > ? extends Persistent
    > ? extends Object (unfinished POJO implementation)
    > CayenneDataObject (as in "generic persistence" [1])
    > DataRow
    > scalar
    > Object[] (a mix of scalars and any of the above)
    >
    > I don't see how we can easily parameterize that in a meaningful way.
    >
    > So my vote is to postpone this till 3.1 and make it a 3.1 priority
    > to create an appropriate generics based query design, and maybe
    > reduce the number of options. I don't think significantly delaying
    > and radically changing 3.0 (that has been de-facto stable for some
    > time) is a good idea.
    >
    > Andrus
    >
    > [1] http://cayenne.apache.org/doc/generic-persistent-class.html
    >
    >



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