Command vs Query

[rkqiku]

Question

Does it make more sense to separate Queries and Commands?
Currently, everything is named as command.
I mean, is it better to name GET as Queries (GetCarQuery) and POST, PUT etc as Commands (PostCarCommand)?

Project template

API

Environment

[RehanSaeed]

They're named Command after the command pattern. Commands and queries correspond more with the CQRS pattern which the templates don't implement but they could I suppose.

@VictorioBerra what do you think? I'm not sure if this should be the new default, it does make sense somewhat.

[VictorioBerra]

I almost replied to this yesterday but wanted to see your thoughts @RehanSaeed if we are talking about a simple move+rename, I think thats just fine. @rkqiku send a PR.

I checked other CQRS sample repos and notice this pattern: https://github.com/kgrzybek/sample-dotnet-core-cqrs-api/tree/master/src/SampleProject.API/Orders/GetCustomerOrderDetails (GetCustomerOrderDetailsQuery.cs)

Alternatively, I see people make a new folder for Queries and keep them separate like that, which seems nice.

[RehanSaeed]

I was thinking of a straight rename. If I was going to do subfolders, Wouldn't you prefer to make subfolders based on the controller name:

Commands
    Foo
        WooCommand.cs
        WooQuery.cs
    Bar
        WaaCommand.cs
        WaaQuery.cs
Controllers
    FooController.cs
    BarController.cs

As opposed to this Commands and Queries below?

Commands
    WooCommand.cs
    WaaCommand.cs
Queries
    WooQuery.cs
    WaaQuery.cs

[VictorioBerra]

@RehanSaeed there's definitely a trend doing it the first way I have noticed, naming folders by feature. I like the first way but either works!

[rkqiku]

Thanks a lot for your feedbacks! I will try my first PR here.
Maybe second one fits better @RehanSaeed
Every time I discuss separation by Features vs Components this comes into my mind https://pbs.twimg.com/media/DZXxze3XcAA1dbv?format=jpg&name=medium

[RehanSaeed]

I thought about this some more. The beginning of the file has the HTTP method in it Get, Post, Patch etc. That provides more information than just Command and Query and there is some duplication of meaning i.e. a GET is a Query and everything else is a Command. So I'm not too sure it is that useful anymore.

[disklosr]

If you're going to do it the CQRS I think there's value in distinguishing commands vs queries at the class name and file name level. Also, I don't think the mapping between http verbs and query/command is a duplication. It sure maps naturally in most cases but it's easy to imagine exceptions to the rule (a POST request mapped to a query)

[RehanSaeed]

Sorry for coming back to this after some time. Things got on top of me.

If you go with class name e.g. GetFooQuery or PostFooCommand. That seems ok. What folder structure would you go with though?

There is a danger that people are going to get confused between the command pattern and CQRS pattern because both use the word 'Command'. Ideally, I'd like to avoid that somehow.