Understanding PUT-Requests
The PUT method is a core component of the HTTP protocol, specifically designed for CRUD operations within a REST-API. Its primary purpose is to update an existing resource or create a resource at a known URI. When a client sends a PUT request, it typically includes a complete JSON or XML representation of the resource in the request body.
One of the most important concepts regarding this method is Idempotency. As defined by MDN Web Docs, an idempotent operation is one where multiple identical requests have the same effect as a single request. This contrasts with the POST method, where repeated requests might result in the creation of duplicate records. If the server successfully updates a resource, it usually returns a 200 (OK) or 204 (No Content) status code. If the Server successfully creates a new resource at the specified Endpoint, a 201 (Created) response is expected, as detailed in the RFC 7231 standard.
Developers must distinguish PUT from the PATCH method. While PUT replaces the entire resource state, PATCH is used for partial updates. For example, if a client only needs to change a user's email address without sending the full profile data, PATCH is more efficient, whereas PUT would require the entire user object to be sent to avoid accidental data loss or resetting fields to default values.