IT:AD:Patterns:SOLID/LSP
LSP
Interfaces! Everything in the real world is done by Contract (ie Interfaces). You buy a bus ticket…and have no idea who will be your bus driver today. So why should you classes be so tightly tied to a named class?
They shouldn’t. They should never deal with SqlDataReader – but IDataReader.
Who the Heck is Liskov?
Barbara Liskov. Provided some key practical and theoretical tools and methods for distributed programming, specifically contributing to the design of programming languages and techniques for data abstraction that hide the complexity of how data is stored and manipulated so as to make life easier for programmers. She has also worked on fault tolerance, an important property of distributed programs that allows them to continue to function in the presence of partial failure. Ref: http://blog.prof.so/2013/02/computerscientists.html