BLL & DAL: How are they different?

[Mark Rae [MVP]]

I don't have to change my DAL for any specific application.

Me neither...

I only change it if there is a TSQL change.

I don't even have to do that...

 

[Mark Rae [MVP]]

How do you manage shifts between database servers or even other storage
mediums (webservices, etc.) with this though?

Factory pattern...

IMO this is contrary to the purpose of abstraction as you are placing Data
Access implementation details inside your BLL.

My BLL interfaces with my DAL, never directly with the RDBMS...

It's great if you only have one place in your BLL where that data is
accessed,

??? My BLL interfaces with my DAL all over the place - everywhere it needs
to, in fact...

but what about cases where you need a different solution to retrieve your
data

Factory pattern...