Introducing CQRS into Legacy Code

Stefan Priebsch | The Online PHP Conference |

Getter methods retrieve state, while setter methods change state. We all know that. HTTP GET requests retrieve state, while HTTP POST requests change state. We all know that. Then why have we built so many applications with a single object model, blatantly ignoring this separation? Turns out that creating separate models for queries and commands makes a lot of sense. But how can we introduce this concept into legacy applications?