REST - Shouldn't PUT = Create and POST = Update

Question

Shouldn't PUT be used to Create and POST used to Update since PUT is idempotent.

That way multiple PUTs for the same Order will place only one Order?

Answer 1

The difference is that a PUT is for a known resource, and therefor used for updating, as stated here in rfc2616.

The fundamental difference between the POST and PUT requests is reflected in the different meaning of the Request-URI. The URI in a POST request identifies the resource that will handle the enclosed entity. That resource might be a data-accepting process, a gateway to some other protocol, or a separate entity that accepts annotations. In contrast, the URI in a PUT request identifies the entity enclosed with the request -- the user agent knows what URI is intended and the server MUST NOT attempt to apply the request to some other resource.

I do see where you are coming from based on the names themselves however.

I usually look at POST as it should be the URI that will handle the content of my request (in most cases the params as form values) and thus creating a new resource, and PUT as the URI which is the subject of my request (/users/1234), a resource which already exists.

I believe the nomenclature goes back a long ways, consider the early web. One might want to POST their message to a message board, and then PUT additional content into their message at a later date.