Domain queries in CQRS

Posted by JontyMC on Stack Overflow See other posts from Stack Overflow or by JontyMC
Published on 2010-01-06T19:06:34Z Indexed on 2010/04/08 10:53 UTC
Read the original article Hit count: 967

Filed under:

ddd

|

cqrs

We are trying out CQRS. We have a validation situation where a CustomerService (domain service) needs to know whether or not a Customer exists. Customers are unique by their email address. Our Customer repository (a generic repository) only has Get(id) and Add(customer). How should the CustomerService find out if the Customer exists?

© Stack Overflow or respective owner

Related posts about ddd

Implement DDD and drawing the line between the an Entity and value object

as seen on Stack Overflow - Search for 'Stack Overflow'
I am implementing an EMR project. I would like to apply a DDD based approach to the problem. I have identified the "Patient" as being the core object of the system. I understand Patient would be an entity object as well as an aggregrate. I have also identified that every patient must have a… >>> More
DDD with Grails

as seen on Stack Overflow - Search for 'Stack Overflow'
I cannot find any info about doing Domain Driven Design (DDD) with Grails. I'm looking for any best practices, experience notes or even open source projects that are good examples of DDD with Grails. >>> More
in DDD (gdb) how to skip passed loops

as seen on Stack Overflow - Search for 'Stack Overflow'
During many, sometimes inundating, debugging sessions using DDD, I stumble upon loops. And I keep pressing next to get passed it, and if there are many iterations, I just set a break point right after it, and press "continue." Is there any other way to go passed loops? Thanks >>> More
in DDD (gdb) how to skip past loops

as seen on Stack Overflow - Search for 'Stack Overflow'
During many, sometimes inundating, debugging sessions using DDD, I stumble upon loops. And I keep pressing next to get past it, and if there are many iterations, I just set a break point right after it, and press "continue." Is there any other way to go past loops? Thanks >>> More
Service Oriented Architecture & Domain-Driven Design

as seen on Stack Overflow - Search for 'Stack Overflow'
I've always developed code in a SOA type of way. This year I've been trying to do more DDD but I keep getting the feeling that I'm not getting it. At work our systems are load balanced and designed not to have state. The architecture is: Website ===Physical Layer== Main Service ==Physical Layer== Server… >>> More

Related posts about cqrs

CQRS at Jax Code Camp 2012

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Continuing my CQRS world tour...I gave my CQRS presentation at the Jax Code Camp 2012 this past Saturday. It was a great crowd with lots of representation from the wicked smart engineers at Feature[23] and others from the Jacksonville developer community. If you'd like to take a… >>> More
CQRS without using others patterns

as seen on Programmers - Search for 'Programmers'
I would like to explain CQRS to my team of developers. I just can't figure out how to explain it in the simplest way so they can implement the pattern rapidly without any others frameworks. I've read a lot of resources including video and articles but I don't find how to implement CQRS without using… >>> More
Domain queries in CQRS

as seen on Stack Overflow - Search for 'Stack Overflow'
We are trying out CQRS. We have a validation situation where a CustomerService (domain service) needs to know whether or not a Customer exists. Customers are unique by their email address. Our Customer repository (a generic repository) only has Get(id) and Add(customer). How should the CustomerService… >>> More
CQRS - The query side

as seen on Stack Overflow - Search for 'Stack Overflow'
A lot of the blogsphere articles related to CQRS (command query repsonsibility) seperation seem to imply that all screens/viewmodels are flat. e.g. Name, Age, Location Of Birth etc.. and thus the suggestion that implementation wise we stick them into fast read source etc.. single table per view mySQL… >>> More
CQRS event versioning

as seen on Stack Overflow - Search for 'Stack Overflow'
Versioning If your events changes you would create a new version of that event, and keep the old ones. To keep your domain code form being bloated with handling of all versions of events you would basically introduce a component that converts your events from previous to newer versions, and then… >>> More