In my own code I do something similar to what DBUtils does -- borrowing a
page from the Grails domain object design. I put the mapping between the
fields and the table columns in a Map within the bean. This allows me to
explicitly state the mapping between the two -- or rather explicitly state
the exceptions to the basic mapping rule. This does the trick for me.
Mark
On Tue, Feb 24, 2009 at 1:49 PM, Christian Hvid <christian.h...@gmail.com>wrote:
>
> DBUtils code look like this:
>
> QueryRunner run = new QueryRunner(dataSource);
>
> ResultSetHandler h = new BeanHandler(Person.class);
>
> Person p = (Person) run.query("SELECT * FROM Person WHERE name=?",
> "John Doe", h);
>
> (Which implictly calls the public no arguments constructor of People
> and some setters thereafter.)
>
> I avoided that approach because it hardwires the attribute names of
> the relation returned by the query with the properties of the Java
> class.
>
> So if something is called given_name in a database table there would
> have to be a setGivenName (or maybe even setGiven_name) in the Java
> class.
>
> Also you would have to have public setters for all properties -
> eventhough it only makes sense setting them at construction (i.e.
> "id").
>
> On Feb 24, 4:27 pm, Mark Fortner <phidia...@gmail.com> wrote:
> > Hi Christian,
> > You might want to have a look at Apache Commons DBUtils which uses
> similar
> > syntax to convert resultsets into beans using a the BeanProcessor class.
> >
> > Hope this helps,
> >
> > Mark
> >
> > On Sun, Feb 22, 2009 at 6:21 AM, Christian Hvid <
> christian.h...@gmail.com>wrote:
> >
> >
> >
> >
> >
> > > Hi Java people.
> >
> > > I have been toying with simplier ways of doing embedded SQL in Java.
> >
> > > And would like your comments on this one?
> >
> > >http://code.google.com/p/chalkmine/
> >
> > > It allows you to write code like this:
> >
> > > openConnection();
> > > try {
> > > int count = queryScalar(Integer.class, "select count(*) from
> > > people");
> > > System.out.println("There are "+count+" people in the bin.");
> > > } finally {
> > > closeConnection();
> > > }
> >
> > > or
> >
> > > openConnection();
> > > try {
> > > List<Person> people = queryList(Person.class, "select name,
> > > time_in_the_bin from people");
> > > for (Person p : people)
> > > System.out.println(p.getName()+" has been "+p.getTimeInTheBin()
> > > +" hours in the bin.");
> > > } finally {
> > > closeConnection();
> > > }
> >
> > > (Provided that Person has a constructor matching the types of name,
> > > time_in_the_bin. Probably Person(String, int).)
> >
> > > Where the methods openConnection, queryScalar, queryList,
> > > closeConnection are statically imported.
> >
> > > openConnection() figures out the name of the calling class, looks up a
> > > configuration, opens a connection and puts in a ThreadLocal container.
> >
> > > queryScalar(Class, String, ...) performs a query with a single row
> > > result that is "cast" to the given class.
> >
> > > queryList(Class, String, ...) performs a query and returns the result
> > > as a list of the given class.
> >
> > > I would like to turn it into a full-fledged open source project.
> >
> > > But since it is incredibly hard for a new open source project to gain
> > > traction I would like to figure out whether it is interesting enough
> > > first.
> >
> > > -- Christian
> >
> > --
> > Mark Fortner
> >
> > blog:http://feeds.feedburner.com/jroller/ideafactory
> >
>
--
Mark Fortner
blog: http://feeds.feedburner.com/jroller/ideafactory
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