Отладка FastAPI‑приложения с SQLAlchemy

Найдите и исправьте ошибки в следующем примере кода FastAPI, использующего SQLAlchemy.

from fastapi import FastAPI, HTTPException, Depends
from sqlalchemy import create_engine, Column, Integer, String, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, relationship, Session
from typing import List

DATABASE_URL = "sqlite:///./test.db"

engine = create_engine(DATABASE_URL)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()

app = FastAPI()

class User(Base):
    __tablename__ = "users"
    id = Column(Integer, primary_key=True, index=True)
    name = Column(String, index=True)
    email = Column(String, index=True)
    items = relationship("Item", back_populates="owner")

class Item(Base):
    __tablename__ = "items"
    id = Column(Integer, primary_key=True, index=True)
    title = Column(String, index=True)
    description = Column(String, index=True)
    owner_id = Column(Integer, ForeignKey("users.id"))
    owner = relationship("User", back_populates="items")

Base.metadata.create_all(bind=engine)

from pydantic import BaseModel

class ItemCreate(BaseModel):
    title: str
    description: str

class UserCreate(BaseModel):
    name: str
    email: str

class UserResponse(BaseModel):
    id: int
    name: str
    email: str
    class Config:
        orm_mode = True

@app.post("/users/", response_model=UserResponse)
def create_user(user: UserCreate, db: Session = Depends(get_db)):
    db_user = User(name=user.name, email=user.email)
    db.add(db_user)
    db.commit()
    db.refresh(db_user)
    return db_user

@app.post("/users/{user_id}/items/", response_model=ItemCreate)
def create_item_for_user(
    user_id: int, item: ItemCreate, db: Session = Depends(get_db)
):
    db_item = Item(**item.dict(), owner_id=user_id)
    db.add(db_item)
    db.commit()
    db.refresh(db_item)
    return db_item

@app.get("/users/", response_model=List[UserResponse])
def read_users(skip: int = 0, limit: int = 10, db: Session = Depends(get_db)):
    users = db.query(User).offset(skip).limit(limit).all()
    return users

@app.get("/items/{item_id}", response_model=ItemCreate)
def read_item(item_id: int, db: Session = Depends(get_db)):
    item = db.query(Item).filter(Item.id == item_id).first()
    if item is None:
        raise HTTPException(status_code=404, detail="Item not found")
    return item

@app.put("/items/{item_id}", response_model=ItemCreate)
def update_item(item_id: int, item: ItemCreate, db: Session = Depends(get_db)):
    db_item = db.query(Item).filter(Item.id == item_id).first()
    if db_item is None:
        raise HTTPException(status_code=404, detail="Item not found")
    db_item.title = item.title
    db_item.description = item.description
    db.commit()
    return db_item

@app.delete("/items/{item_id}", response_model=ItemCreate)
def delete_item(item_id: int, db: Session = Depends(get_db)):
    db_item = db.query(Item).filter(Item.id == item_id).first()
    if db_item is None:
        raise HTTPException(status_code=404, detail="Item not found")
    db.delete(db_item)
    db.commit()
    return db_item

@app.get("/users/{user_id}/items", response_model=List[ItemCreate])
def read_items_for_user(user_id: int, db: Session = Depends(get_db)):
    user = db.query(User).filter(User.id == user_id).first()
    if user is None:
        raise HTTPException(status_code=404, detail="User not found")
    return user.items

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()