Design question: transferring data between business objects and the data layer

[olduncleamos]

Hi all,

What is, in general, the preferred practice to transfer data between
business objects and the data layer? To be more specific, I have a
couple of business objects with state data that are stored in external
storage. The data layer take care of communicating with the storage and
return data in dataset or file stream or simple arrays. Have the
business objects directly consume a dataset seems inflexible. What
would be the prefered way of handling this most common situation?

To take this discussion further, let say that the current requirments
only requires data to come from a single source. But it is clear that
different data sources will be needed down the road. Would this extra
consideration impact your design? If so, how?

Thanks for all the suggestion and discussion in advance.

 

[Tom Shelton]

Hi all,

What is, in general, the preferred practice to transfer data between
business objects and the data layer? To be more specific, I have a
couple of business objects with state data that are stored in external
storage. The data layer take care of communicating with the storage and
return data in dataset or file stream or simple arrays. Have the
business objects directly consume a dataset seems inflexible. What
would be the prefered way of handling this most common situation?

To take this discussion further, let say that the current requirments
only requires data to come from a single source. But it is clear that
different data sources will be needed down the road. Would this extra
consideration impact your design? If so, how?

Thanks for all the suggestion and discussion in advance.

Lately, I've been playing with NHibernate for this sort of thing.

www.hibernate.org

 

[Michael Nemtsev]

Hello olduncleamos,

o> What is, in general, the preferred practice to transfer data between
o> business objects and the data layer? To be more specific, I have a
o> couple of business objects with state data that are stored in
o> external storage. The data layer take care of communicating with the
o> storage and return data in dataset or file stream or simple arrays.

o> Have the business objects directly consume a dataset seems
o> inflexible. What would be the prefered way of handling this most
o> common situation?

Everything depends on your requirements - if they are always (that usually
ends up they are not in some time later) will be physically nearby there
is no bad to consume DL directly. And it's not the problem to distribute
them later with using WS/COM+/.NET Remoting, the problem is the interface
for the communication - your all data communications should be performed
through well-known (read published) contract (read interfaces)


o> To take this discussion further, let say that the current requirments
o> only requires data to come from a single source. But it is clear that
o> different data sources will be needed down the road. Would this extra
o> consideration impact your design? If so, how?

You can create DL Factory class that will be used by BL and will responsible
for creating specific DL objects to do some kind of job or your can incapsulate
your data sources in interfaces - look at the DataBase providers architecture,
your just have the set of interfaces and your are free to know which DB (oracle,
sql) u are using


---
WBR,
Michael Nemtsev :: blog: http://spaces.live.com/laflour

"At times one remains faithful to a cause only because its opponents do not
cease to be insipid." (c) Friedrich Nietzsche

 

[sloan]

See
http://sholliday.spaces.live.com/blog/

5/24/2006 Entry
Custom Objects/Collections and Tiered Development