what http response code for rest service on put method when domain rules invalid

What is the most appropriate response code to return when using the PUT method to update a resource, and the request contains some data that would invalidate the domain rules?

For example, a customer resource must have a name specified. 开发者_StackOverflow社区If an agent tries to issue a PUT without supplying a name I don't want to update the resource, and I want to tell the caller that they need to supply a name.

What HTTP response code?

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How about 422?

"The 422 (Unprocessable Entity) status code means the server understands the content type of the request entity (hence a 415(Unsupported Media Type) status code is inappropriate), and the syntax of the request entity is correct (thus a 400 (Bad Request) status code is inappropriate) but was unable to process the contained instructions. For example, this error condition may occur if an XML request body contains well-formed (i.e., syntactically correct), but semantically erroneous, XML instructions."

RFC 4918, Section 11.2

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The response code is not related to the http method in this case. You should return the same status code as if it had been a POST request. I'd say you should use 400 or 409 (Note: See further discussion of the difference between the two in the comments).

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I would return a 400. Strictly, this is for "malformed syntax" (not invalid data), but in practice the YouTube, Twitter, etc. use it for more generally "bad" requests.