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From Matthew Adams <matt...@matthewadams.me>
Subject Re: New Feature Idea
Date Thu, 03 Nov 2011 22:35:26 GMT
Hi Tim,

We are in the process of standardizing similar functionality, called "type
safe query", which is currently functional, albeit proprietary, in the JDO
RI, DataNucleus:


Check that out and see if it meets your needs.


On Thu, Nov 3, 2011 at 5:21 PM, <tgallagher@mmm.com> wrote:

> Hi,
> I've been working the JDO for about 6 months now.  Prior to that I was
> accessing an RMDBs using a tool I created that built JavaBeans to
> represent the DB tables and to manage those tables. I would then build the
> business logic on top of that.  Using JDO will allow me to expand the
> datastores that I can interact with.  However, moving to JDO means that I
> have to again build a feature I use for about 95% of my DB interaction -
> Query-By-Example (QBE)
> With my previous methods, the JavaBeans kept track of items within the
> beans that have changed.  Whenever I wanted to query a table, I would
> create a JavaBean related to the table, set a few values within the bean
> and then user a general query mechanism that would look a the bean, build
> the required SQL and execute it.  This has been useful for about 95% of my
> DB interaction and greatly reduced the amount of SQL written into the
> business layer.
> Moving to JDO, I no longer have that.  However, I have built that same
> mechanism into my JDO related JavaBeans.  Using JDO I was further able to
> create generic QBE methods for using subqueries,  something I could not do
> before.
> Granted, QBE, does have its limits in that creating a this-or-that kind of
> query is difficult.  My current QBE is limited to "these values" types of
> queries (eg. querying a table based on the table's record id) or, for
> String values, using "Like" functionality.  But my experience with
> database interaction for the last decade is that this covers the vast
> majority of the queries.
> I would like to discuss this further with you to determine who this kind
> of functionality can be included in the spec so that I don't have to keep
> re-inventing it with every new datastore access technology.  I can show
> you examples of what we do here at 3M and go over what is required to make
> this work.
> Thanks,
> Tim Gallagher
> Clinical & Economic Research
> 3M Health Information Systems
> 5000 Buttercup Drive
> Castle Rock, CO 80109
> Phone: (303) 814-3867


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