One-page reference for REST, Python (FastAPI/Flask), Node.js/Nest.js, and SQL/NoSQL.

REST

Method Use Idempotent
GET Read Yes
POST Create No
PUT Replace Yes
PATCH Partial No*
DELETE Delete Yes

Status: 200 OK, 201 Created, 204 No Content, 400 Bad Request, 401 Unauthorized, 403 Forbidden, 404 Not Found, 500 Internal Server Error.

URLs: Nouns, plurals (/users), sub-resources (/users/1/orders), query for filter/pagination (?page=2&limit=20).

Python FastAPI

pip install fastapi uvicorn[standard]
uvicorn main:app --reload
  • Docs: /docs (Swagger), /redoc.
  • Params: Path user_id: int, Query skip: int = 0, Body Pydantic model.
  • Errors: raise HTTPException(status_code=404, detail="Not found").
  • DI: Depends(get_db).

Python Flask

pip install flask
python app.py
  • Route: @app.route("/users/<int:id>", methods=["GET","POST"]).
  • Request: request.args, request.get_json(), request.form.
  • Response: return jsonify({...}), 201.
  • Modular: Blueprints, app.register_blueprint(bp).

Node.js (Express)

npm install express
node index.js
  • Route: app.get/post/patch/delete(path, handler).
  • Params: req.params.id, req.query, req.body (after express.json()).
  • Response: res.json(obj), res.status(201).json(obj), res.status(204).send().
  • Errors: next(err) → central errorHandler(err, req, res, next).
  • Modular: app.use('/users', usersRouter).

Nest.js

nest new my-api
npm run start:dev
  • Structure: Module → Controller (HTTP) + Service (logic).
  • Route: @Controller('users'), @Get(), @Post(), @Body(), @Param('id', ParseIntPipe).
  • Validation: DTOs + class-validator, ValidationPipe.
  • Errors: throw new NotFoundException('...').
  • DI: Constructor inject UsersService.

SQL (Backend usage)

  • Python: SQLAlchemy (engine, session, models, text() for raw).
  • Node: Prisma (prisma.user.findMany(), prisma.user.create(), $queryRaw).
  • Rules: Parameterized queries only; use migrations; index hot columns.

NoSQL (Backend usage)

  • MongoDB: Document store; PyMongo/Motor (Python), mongodb driver/Mongoose (Node).
  • Redis: Key-value/cache; redis-py (Python), ioredis/node-redis (Node); use TTL for cache/session.

Module Index

# Topic Path
1 RESTful API 01_restful_api/
2 FastAPI 02_python_fastapi/
3 Flask 03_python_flask/
4 Node.js 04_nodejs/
5 Nest.js 05_nestjs/
6 SQL 06_sql/
7 NoSQL 07_nosql/

See README.md for full overview and learning path.