Merge pull request #524 from realpython/crud-operations

Add materials for the CRUD tutorial

Author: brendaweles

crud-operations/README.md

@@ -0,0 +1,74 @@
+# What Are CRUD Operations?
+
+This repository contains code related to the Real Python tutorial on [CRUD operations](https://realpython.com/crud-operations/).
+
+## Setup
+
+You should first create a virtual environment:
+
+```console
+$ python -m venv venv
+$ source venv/bin/activate
+```
+
+Install the pinned dependencies from `requirements.txt`:
+
+```console
+(venv) $ python -m pip install -r requirements.txt
+```
+
+Then you can execute `crud_sql_alchemy.py` to create a new database:
+
+```sh
+(venv) $ python crud_sql_alchemy.py
+```
+
+This will create a `birds.db` database that you can use to try out CRUD operations.
+
+## Examples
+
+Start a new [Python REPL](https://realpython.com/python-repl/) to perform CRUD operations with raw SQL:
+
+```pycon
+>>> from crud_sql import connect_to_db
+>>> connection = connect_to_db("birds.db")
+>>> create_birds = """
+... INSERT INTO
+...   bird (name)
+... VALUES
+...   ('Hummingbird'),
+...   ('Sugar Glider');
+... """
+>>> connection.execute(create_birds)
+<sqlite3.Cursor object at 0x105027bc0>
+
+>>> connection.commit()
+>>> connection.close()
+```
+
+You can also use SQL Alchemy to interact with the database:
+
+```pycon
+>>> from crud_sql_alchemy import Session, Bird, init_db
+>>> init_db()
+>>> session = Session()
+>>> new_bird = Bird(name="Test Bird")
+>>> session.add(new_bird)
+>>> session.commit()
+```
+
+If you're curious to explore CRUD operations with a REST API, then you can run this command in the terminal:
+
+```console
+(venv) $ uvicorn crud_fastapi:app
+```
+
+Once the server is running, you can test out the Rest API endpoints by visiting `http://127.0.0.1:8000/docs` in your browser.
+
+## Author
+
+- **Philipp Acsany**, E-mail: [[email protected]]([email protected])
+
+## License
+
+Distributed under the MIT license. See [`LICENSE`](../LICENSE) for more information.

crud-operations/crud_fastapi.py

@@ -0,0 +1,80 @@
+from fastapi import FastAPI, HTTPException, Depends
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+from pydantic import BaseModel, ConfigDict
+
+from crud_sql_alchemy import Bird, init_db
+from crud_sql_alchemy import Session as SessionLocal
+
+app = FastAPI()
+init_db()
+
+
+class BirdCreate(BaseModel):
+    name: str
+
+
+class BirdUpdate(BaseModel):
+    name: str
+
+
+class BirdResponse(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: int
+    name: str
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+@app.post("/birds/", response_model=BirdResponse)
+def create_bird(bird: BirdCreate, db: Session = Depends(get_db)):
+    new_bird = Bird(name=bird.name)
+    db.add(new_bird)
+    db.commit()
+    db.refresh(new_bird)
+    return new_bird
+
+
+@app.get("/birds/", response_model=list[BirdResponse])
+def read_birds(db: Session = Depends(get_db)):
+    birds = db.execute(select(Bird)).scalars().all()
+    return birds
+
+
+@app.get("/birds/{bird_id}", response_model=BirdResponse)
+def read_bird(bird_id: int, db: Session = Depends(get_db)):
+    query = select(Bird).where(Bird.id == bird_id)
+    found_bird = db.execute(query).scalar_one()
+    if found_bird is None:
+        raise HTTPException(status_code=404, detail="Bird not found")
+    return found_bird
+
+
+@app.put("/birds/{bird_id}", response_model=BirdResponse)
+def update_bird(bird_id: int, bird: BirdUpdate, db: Session = Depends(get_db)):
+    query = select(Bird).where(Bird.id == bird_id)
+    found_bird = db.execute(query).scalar_one()
+    if found_bird is None:
+        raise HTTPException(status_code=404, detail="Bird not found")
+    found_bird.name = bird.name
+    db.commit()
+    db.refresh(found_bird)
+    return found_bird
+
+
+@app.delete("/birds/{bird_id}", response_model=dict)
+def delete_bird(bird_id: int, db: Session = Depends(get_db)):
+    query = select(Bird).where(Bird.id == bird_id)
+    found_bird = db.execute(query).scalar_one()
+    if found_bird is None:
+        raise HTTPException(status_code=404, detail="Bird not found")
+    db.delete(found_bird)
+    db.commit()
+    return {"message": "Bird deleted successfully"}

crud-operations/crud_sql.py

@@ -0,0 +1,17 @@
+import sqlite3
+
+
+def connect_to_db(db_path):
+    return sqlite3.connect(db_path)
+
+
+if __name__ == "__main__":
+    with connect_to_db("birds.db") as connection:
+        connection.execute(
+            """
+          CREATE TABLE IF NOT EXISTS bird (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            name TEXT NOT NULL
+          );
+        """
+        )

crud-operations/crud_sql_alchemy.py

@@ -0,0 +1,23 @@
+from sqlalchemy import create_engine, Column, Integer, String
+from sqlalchemy.orm import DeclarativeBase, sessionmaker
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+class Bird(Base):
+    __tablename__ = "bird"
+    id = Column(Integer, primary_key=True)
+    name = Column(String)
+
+    def __repr__(self):
+        return f"Bird(id={self.id}, name={self.name!r})"
+
+
+engine = create_engine("sqlite:///birds.db")
+Session = sessionmaker(bind=engine)
+
+
+def init_db():
+    Base.metadata.create_all(engine)

crud-operations/requirements.txt

@@ -0,0 +1,19 @@
+annotated-types==0.6.0
+anyio==4.3.0
+click==8.1.7
+fastapi==0.110.1
+h11==0.14.0
+httptools==0.6.1
+idna==3.7
+pydantic==2.6.4
+pydantic_core==2.16.3
+python-dotenv==1.0.1
+PyYAML==6.0.1
+sniffio==1.3.1
+SQLAlchemy==2.0.29
+starlette==0.37.2
+typing_extensions==4.10.0
+uvicorn==0.29.0
+uvloop==0.19.0
+watchfiles==0.21.0
+websockets==12.0