PUT and DELETE operations

Introduction to FastAPI

Matt Eckerle

Software and Data Engineering Leader

PUT vs. DELETE

PUT Operations

Traditional use: update an existing object
Parameters sent via query string as well as request body
Requires an application or framework
- e.g. cURL, requests

api = "http://moviereviews.co/reviews/1"
body = {"text": "A fantastic movie!"}
response = requests.put(api, json=body)

DELETE Operations

Traditional use: delete an existing object
Parameters sent via query string as well as request body
Requires an application or framework
- e.g. cURL, requests

api = "http://moviereviews.co/reviews/1"
response = requests.delete(api)

Referencing Existing Objects

No ORM, so app must map object to ID
Database ID - unique identifier
_id convention for database IDs
- review_id: Table reviews, column id
- Same convention in frameworks with ORM

from pydantic import BaseModel

class DbReview(BaseModel):
    movie: str
    num_stars: int
    text: str
    # Reference database ID of Reviews
    review_id: int

Handling a PUT Operation

PUT endpoint to update an existing movie review:

Endpoint: /reviews
Input: DbReview (from previous slide)
Output: DbReview

@app.put("/reviews", response_model=DbReview)
def update_review(review: DbReview):
    # Update the movie review in the database
    db_review = crud.update_review(review)
    # Return the updated review
    return db_review

Handling a DELETE Operation

DELETE endpoint to remove an existing movie review:

Endpoint: /reviews
Input: DbReview
Output: {}

@app.delete("/reviews")
def delete_review(review: DbReview):
    # Delete the movie review from the database
    crud.delete_review(review)
    # Return nothing since the data is gone
    return {}

Let's practice!

Introduction to FastAPI