-
Starting at the beginning of 2009, a series of blog posts by Casey Charlton Blogged The Ubiquitous Language Blogged Entities and Value Objects Blogged Bounded Contexts Blogged There Is No Database Blogged Command Query Separation as an Architectural Concept Blogged Entities and Value Objects Blogged...
-
Continuing our series on Domain Driven Design, we now get to one of the more interesting patterns in DDD – the Specification . A Specification is, in simple terms, a small piece of logic that sits on it’s own and gives an answer to a simple question … “does this match?”...
-
Do not try to bend the spoon; that's impossible. Instead only try to realize the truth: There is no spoon. The Matrix Again prompted by discussion on the DDD Yahoo list, this post is intended to explain what on the face of it is a pretty dumb assertion - there is no database in DDD! I'm sure...
-
I seem to have taken a fairly long time to get here, and it has been mentioned in passing, but now we get to the last major part of the Domain Driven Design picture – Repository . In traditional architectures, your application talks to some kind of database layer, and asks it to save or retrieve...
-
There can be no word more common in development, and no word used for such a multitude of different things as “service” It was therefore unfortunate that Eric Evans introduced yet another concept of Service in DDD, one which has since been referred to by some as a Domain Service . However...
-
In many conversations, and in many comments here, you hear phrases like “well that’s not really suited to DDD” or “DDD isn’t the best fit for that problem”. You even see those kind of comments on my blog, and often they are posted by me. This obviously leaves a number...
-
No, not that Enterprise! The other Enterprise – the big amorphous one that organisation spent a fortune putting SOA around. Domain Driven Design appears to be at odds with large scale distributed systems, it is after all methodology to design and write application software, and in SOA we don’t...
-
We are family I got all my sisters with me Sister Sledge Some things belong together, like Apple Pie and Ice Cream, or Sonny and Cher. And so it is with Entities and Value Objects (VOs) – some of them belong together. Aggregates are groups of things that belong together. An Aggregate Root is the...
-
There has been some confusion recently around a recent evolution of DDD, the idea of Command Query Separation (CQS) at the architectural level. This post is yet again jumping ahead into the “advanced” stuff, so go ahead and skip this if you just want to get the basics down first… those...
-
It was brought up indirectly in a comment on my last post … the idea of a [[ Ubiquitous Language]] seems like it is too all encompassing. Indeed it is – unless you are working on a very simple application, one language just isn’t enough. Not only that, but a single “mammoth model”...