What is the difference between PUT, POST and PATCH

What is the difference between PUT, POST and PATCH methods in HTTP protocol?

POST

HTTP.POST can be used when the client is sending data to the server and the server will decide the URI for the newly created resource. The POST method is used to request that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI in the Request-Line.

PUT

HTTP.PUT can be used when the client is sending data to the server and the client is determining the URI for the newly created resource. The PUT method requests that the enclosed entity be stored under the supplied Request-URI. If the Request-URI refers to an already existing resource, the enclosed entity SHOULD be considered as a modified version of the one residing on the origin server. If the Request-URI does not point to an existing resource, and that URI is capable of being defined as a new resource by the requesting user agent, the origin server can create the resource with that URI.

PATCH

HTTP.PATCH can be used when the client is sending one or more changes to be applied by the server. The PATCH method requests that a set of changes described in the request entity be applied to the resource identified by the Request-URI. The set of changes is represented in a format called a patch document.

For more information refer below mentioned URL

PUT vs. POST in REST

https://youtu.be/m9WyV7D89us

Difference between PUT, POST, GET, DELETE and PATCH IN HTTP Verbs:

The most commonly used HTTP verbs POST, GET, PUT, DELETE are similar to CRUD (Create, Read, Update and Delete) operations in database. We specify these HTTP verbs in the capital case. So, the below is the comparison between them.

create - POST
read - GET
update - PUT
delete - DELETE

PATCH: Submits a partial modification to a resource. If you only need to update one field for the resource, you may want to use the PATCH method.

Note:
Since POST, PUT, DELETE modifies the content, the tests with the fiddler for the below url just mimicks the updations. It doesn't delete or modify actually. We can just see the status codes to check whether insertions, updations, deletions occur.

URL: http://jsonplaceholder.typicode.com/posts/

1) GET:

GET is the simplest type of HTTP request method; the one that browsers use each time you click a link or type a URL into the address bar. It instructs the server to transmit the data identified by the URL to the client. Data should never be modified on the server side as a result of a GET request. In this sense, a GET request is read-only.

Checking with Fiddler or PostMan: We can use the fiddler for checking the response. Open the fiddler and select the Compose tab. Specify the verb and url as shown below and click Execute to check the response.

Verb: GET

url: http://jsonplaceholder.typicode.com/posts/

Response: You will get the response as:

"userId": 1, "id": 1, "title": "sunt aut...", "body": "quia et suscipit..."

In the “happy” (or non-error) path, GET returns a representation in XML or JSON and an HTTP response code of 200 (OK). In an error case, it most often returns a 404 (NOT FOUND) or 400 (BAD REQUEST).

2) POST:

The POST verb is mostly utilized to create new resources. In particular, it's used to create subordinate resources. That is, subordinate to some other (e.g. parent) resource.

On successful creation, return HTTP status 201, returning a Location header with a link to the newly-created resource with the 201 HTTP status.

Checking with Fiddler or PostMan: We can use the fiddler for checking the response. Open the fiddler and select the Compose tab. Specify the verb and url as shown below and click Execute to check the response.

Verb: POST

url: http://jsonplaceholder.typicode.com/posts/

Request Body:

data: { title: 'foo', body: 'bar', userId: 1000, Id : 1000 }

Response: You would receive the response code as 201.

If we want to check the inserted record with Id = 1000 change the verb to Get and use the same url and click Execute.

As said earlier, the above url only allows reads (GET), we cannot read the updated data in real.

3) PUT:

PUT is most-often utilized for update capabilities, PUT-ing to a known resource URI with the request body containing the newly-updated representation of the original resource.

Checking with Fiddler or PostMan: We can use the fiddler for checking the response. Open the fiddler and select the Compose tab. Specify the verb and url as shown below and click Execute to check the response.

Verb: PUT

url: http://jsonplaceholder.typicode.com/posts/1

Request Body:

data: { title: 'foo', body: 'bar', userId: 1, Id : 1 }

Response: On successful update it returns 200 (or 204 if not returning any content in the body) from a PUT.

4) DELETE:

DELETE is pretty easy to understand. It is used to delete a resource identified by a URI.

On successful deletion, return HTTP status 200 (OK) along with a response body, perhaps the representation of the deleted item (often demands too much bandwidth), or a wrapped response (see Return Values below). Either that or return HTTP status 204 (NO CONTENT) with no response body. In other words, a 204 status with no body, or the JSEND-style response and HTTP status 200 are the recommended responses.

Checking with Fiddler or PostMan: We can use the fiddler for checking the response. Open the fiddler and select the Compose tab. Specify the verb and url as shown below and click Execute to check the response.

Verb: DELETE

url: http://jsonplaceholder.typicode.com/posts/1

Response: On successful deletion it returns HTTP status 200 (OK) along with a response body.

Example between PUT and PATCH

PUT

If I had to change my firstname then send PUT request for Update:

{ "first": "Nazmul", "last": "hasan" } So, here in order to update the first name we need to send all the parameters of the data again.

PATCH:

Patch request says that we would only send the data that we need to modify without modifying or effecting other parts of the data. Ex: if we need to update only the first name, we pass only the first name.

Please refer the below links for more information:

https://jsonplaceholder.typicode.com/

https://github.com/typicode/jsonplaceholder#how-to

What is the main difference between PATCH and PUT request?

http://www.restapitutorial.com/lessons/httpmethods.html

PUT = replace the ENTIRE RESOURCE with the new representation provided

PATCH = replace parts of the source resource with the values provided AND|OR other parts of the resource are updated that you havent provided (timestamps) AND|OR updating the resource effects other resources (relationships)

https://laracasts.com/discuss/channels/general-discussion/whats-the-differences-between-put-and-patch?page=1