The PATCH method in a REST API is used to partially update an existing resource on the server.
It allows a client to send a set of changes to be made to a resource, rather than replacing the entire resource as in the PUT method. The PATCH method is also idempotent, meaning that making multiple identical requests will have the same effect as making a single request.
A typical PATCH request will include the following:
- The HTTP verb “PATCH”
- The endpoint or resource location, such as “/products/{product_id}”
- The headers, which may include additional information such as the content type or the authentication information.
- The request body, which contains the data that the client wants to send to the server in order to update the resource. This usually uses a specific format such as JSON Patch or HTTP PATCH.
A typical PATCH response will include the following:
- The HTTP status code, such as 200 OK if the request was successful or 400 Bad Request if the request was malformed or invalid.
- The headers, which may include additional information such as the location of the new resource or the content type.
- The response body, which may contain the updated resource or additional information about the status of the request.
It’s worth noting that the PATCH method is typically used to send a set of changes to be made to a resource, rather than replacing the entire resource as in the PUT method. This allows for more fine-grained updates to be made to a resource and can be more efficient in terms of network traffic and processing power. Additionally, the PATCH method is idempotent, which means that making multiple identical requests will have the same effect as making a single request.