Re: LEFT JOIN avaliable?

From: Mike Kienenberger (mkienen..mail.com)
Date: Wed May 28 2008 - 15:02:37 EDT

  • Next message: Jon Sharp: "Re: Cayenne and JAX-WS / JAXB"

    Read this for outer (left) join support in Cayenne 3.....

    http://cayenne.apache.org/doc/path-expressions.html

    Short version: Put a "+" after the "a.bid=b.bid" relationship path
    name (probably "bid" in your example, so "a.bid+".

    On 5/28/08, Andrey Razumovsky <razumovsky.andre..mail.com> wrote:
    > Hi,
    >
    > Imagine I have tables A and B. A has 'aid', 'aname' and 'bid' (relation to
    > B, which is non-mandatory) fields. B has 'bid' and 'bname'.
    > I want to make a selection from A but order it by 'bname'. When there is no
    > B related, 'bname' must be treated as '', i.e.
    > SELECT aid, aname FROM a LEFT JOIN b ON (a.bid=b.bid) ORDER BY bname.
    >
    > That's fine in SQL, but i can't find out how this is to be made with mapped
    > classes in Cayenne, because when i add an ordering, Cayenne creates query
    > with simple JOIN, and I need LEFT JOIN here.So how can i tell Cayenne to
    > create LEFT JOIN instead? I'd prefer using SelectQuery, however any other
    > hints will be appreciated too.
    >
    > Thanks,
    >
    > Andrey
    >



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