Since I have transitioned from a world of
spaghetti code through the land of the uber-cfc, and finally onto some
OO concepts, I have tried to figure out what the best way to create the
business objects and persist them to the database. For nearly ever
application I have developed, I have created the database first, since,
in my mind, understanding the data is the first step to understanding
the way the application will function.
However, in the OO world,
the primary step is to design the business objects. In my latest
project I decided to take one step deeper into the OO world and develop
all my business objects forgetting all about how the database would be
laid out. I had no problems with this, authoring complex objects
containing arrays or instances of other objects without
Then I needed to figure out how to persist them. In the
past, each of my business objects directly mapped to a table in my
database. This made it easy to build a code generator, read in the DB
metadata and, in the words of John Madden, “Boom”, I had my beans, DAOs,
Now, I see what Sean Corfield refers to as the “5:1
Syndrome”. I have a dumb bean object, a DAO, a Gateway, a Service and,
if using Model-Glue, a Controller for nearly every object, and in turn
every table in the database. This always seemed like code bloat to me,
so I was very happy to see other, like Sean, refer to it as such. There
must be a better way!
Trying to avoid this I decided, OK I’ll
use Reactor. Active Record, generated code, sounds good. Then I
realized that I have to create the database first. Back to square
Should business objects reflect the organization of the
database? They can, but if it doesn’t fit the way the business object
is used in the application, then no, it shouldn’t. Also, from the
other way, the best way to organized the business objects is probably
not the best way to organize the database. The database should be in
3NF, avoid duplication whereever possible, etc, etc.
to trash all the BOs I created already, I decided I would write all the
persistance stuff myself. So now that I have some beans, I created a
service for each and wired them up in ColdSpring. I put all the methods
that would normally go in my DAO (save, new, and CRUD) in my service as
well as some getAll() calls.
As a side note, I don’t return
query objects since, even though they are faster than creating an array
of objects, I cant call a complex getter, such as a calculated value
easily, and this allows me to use the same calls to get the data for one
instance of an object as I do for a collection.
Now I have a BO
and a service that is completely separate from the DB. Persisting
complex objects is a bit more complicated than using the 1:1 BO to DB
mapping, but it works. The only issue is, I don’t want to have to
maintain all this manually. I wish we had a mapping tool to handle
persistance from BO to DB without requiring that the DB reflect the BO
or vice versa.
Java has Hibernate to handle this issue. With CF8 we can now use Hibernate with a Java model, but what if we want to
model using CFCs? cfHibernate
attempted to do this and seems to have run into some issues. Can we use
Hibernate to map CF objects to the DB? I am going to attempt to find an
answer for this in the next few weeks for my current project. Hopefully
I can find a solution.