[http] What is the difference between PUT, POST and PATCH?

The below definition is from the real world example.

Example Overview
For every client data, we are storing an identifier to find that client data and we will send back that identifier to that client for reference.

  1. POST

    • If the Client sends data without any identifier using the POST method then we will store it and assign a new identifier.
    • If the Client again sends the same data without any identifier using the POST method, then we will store it and assign a new identifier.
    • Note: Duplication is allowed here
  2. PUT

    • If the Client Sends data with an identifier then we will check whether that identifier exists. If the identifier exists we will update data else we will create it and assign a new identifier.
  3. PATCH

    • If the Client Sends data with an identifier then we will check whether that identifier exists. If the identifier exists we will update data else we will throw an exception.

Note: On Put Method, We are not throwing an exception if an identifier is not found. But in Patch method, we are throwing an exception if the identifier is not found.

Do let me know if you have any queries on the above.