Data Layer Best Practices

Question

I am in the middle of a \"discussion\" with a colleague about the best way to implement the data layer in a new application.

One viewpoint is that the data layer should

Answer 1

It really depends on your view of the world - I used to be in the uncoupled camp. The DAL was only there to supply data to the BAL - end of story.

With emerging technologies such as Linq to SQL and Entity Framework becoming a bit more popular, then the line between DAL and BAL have been blurred a bit. In L2S especially your DAL is quite tightly coupled to the Business objects as the object model has a 1-1 mapping to your database field.

Like anything in software development there is no right or wrong answer. You need to understand your requirements and future requirments and work from there. I would no more use a Ferrari on the Dakhar rally as I would a Range Rover on a track day.