Well, Cayenne doesn't "force" you to use SQL.
What it /does/ do is to /allow/ you to use SQL.
An app I wrote awhile back had the requirement to generate reports
from tables with on the order of a million records.
There was no substitute for hand crafted, carefully optimized
queries. Cayenne makes it easy to do that, if the need arises, via
SQLTemplate.
But SQLTemplate offers more than "just" SQL. You can script it (via
velocity [http://velocity.apache.org] directives and variables); you
can write customized queries for different backends (MySQL, HSQL,
Oracle, etc.) which then "just work" based on which backend you're
connected to (ie: in your code, you don't have to think about which
backend you're connected to).
But, if you're interested in sticking to object paths and
relationships, EJBQLQuery provides a nice alternative.
Robert
On Apr 8, 2009, at 4/82:27 PM , Weddle, Anthony wrote:
> Thanks, Andrus. I'll take a look at EJBQL and may have to revisit
> SQLTemplates. It's not that the latter is scary, just that it
> appears to
> be native SQL, rather than being able to used property paths and class
> or object entity names. We're using an ORM framework to avoid native
> SQL
> wherever we can, so wouldn't want to switch to a framework that forced
> us back to more of it.
>
> One of the main problems I'm having is that there is so little
> documentation, books and articles about Cayenne. Is there a fairly
> comprehensive list of publications (not necessarily books) on Cayenne?
>
> Tony
>
> -----Original Message-----
> From: Andrus Adamchik [mailto:andru..bjectstyle.org]
> Sent: Wednesday, 8 April 2009 5:46 p.m.
> To: use..ayenne.apache.org
> Subject: Re: General queries
>
> Cayenne 3.0 includes support for EJBQLQuery which seem like you what
> you need here:
>
> http://cayenne.apache.org/doc/ejbqlquery.html
>
> We are following the JPA syntax per JSR-220
> (http://jcp.org/aboutJava/communityprocess/final/jsr220/index.html
> ). At does support aggregates, separate columns, subqueries, etc.
> Anything not supported by the EJBQLQuery will indeed require a
> SQLTemplate, which is not as scary as it sounds.
>
> Hope this helps.
>
> Andrus
>
>
>
>
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