CODEWITHSUNDEEP
restpython-requestsflask-restful
Sir Nutcase
Sir Nutcase

Reputation: 195

Flask:Confused over using PUT/POST in Rest API

Respected Elders/Programmers/Learned-people,
I have read a very popular answer here about using PUT or POST, but I couldn't decipher from it as to what is the correct way to do so. Almost every answer has comments saying this is wrong/this is right. Mighty confused here.
My requirements:
Sending 2 Json files to the server, one to be inserted in Database and other to be updated. I thought I would use PUT to update, and POST to Insert into the database. That way, on the client side itself I would decide whether to insert or update.

Confusion: Since, the client alone is responsible for its data to be created/updated on the server, even POST in my case upon being repeated would insert the same thing (insert into table values) over and over, behaving as idempotent OR would give an error (Because of primary key conflict). Finally, it would not create something new upon firing it twice.

Question: Is it correct to use PUT for updation, and POST for insertion?

Upvotes: 0

Views: 1068

Answers (1)

Evert
Evert

Reputation: 99745

PUT can also be used for creating. What's important is the url. This is generally the accepted pattern:

PUT /collection/1234 <- Update a specific item OR create it
POST /collection <- Add a new item to a collection

Which one is right for you depends on a few things. Does the server determine the url of the new item, or does the client?

If the client can figure out what the url of a new item becomes, using PUT might be better because you can more easily turn it into an idempotent request.

Remember that with a PUT request the intent is always that you are replacing the resource at the target url with a new state.

However, if the server creates the url pattern (maybe you have an auto-incrementing id), POST is better. POST doesn't have to be on the parent collection but it's common.

If you want POST and want idempotence, you need some other way to figure out something was a repeated request. You get that for free with PUT. For example, the Stripe API solves this by adding a non-standard Idempotency-Key header.

Upvotes: 1

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